raw source code
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

class N25 {
        InputStream is;
        PrintWriter out;
        String INPUT = "";

        void solve() {
                int n = ni();
                long[] P = new long[200001];
                for(int i = 0;i < n;i++){
                        P[ni()]++;
                }
                long[] P2 = convolute(P, P);
                int[] primes = sieveEratosthenes(400000);
                long ans = 0;
                for(int p : primes){
                        ans += P2[p];
                }
                out.println((ans - P[1])/2);
        }
        
        public static int[] sieveEratosthenes(int n) {
                if (n <= 32) {
                        int[] primes = { 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31 };
                        for (int i = 0; i < primes.length; i++) {
                                if (n < primes[i]) {
                                        return Arrays.copyOf(primes, i);
                                }
                        }
                        return primes;
                }

                int u = n + 32;
                double lu = Math.log(u);
                int[] ret = new int[(int) (u / lu + u / lu / lu * 1.5)];
                ret[0] = 2;
                int pos = 1;

                int[] isnp = new int[(n + 1) / 32 / 2 + 1];
                int sup = (n + 1) / 32 / 2 + 1;

                int[] tprimes = { 3, 5, 7, 11, 13, 17, 19, 23, 29, 31 };
                for (int tp : tprimes) {
                        ret[pos++] = tp;
                        int[] ptn = new int[tp];
                        for (int i = (tp - 3) / 2; i < tp << 5; i += tp)
                                ptn[i >> 5] |= 1 << (i & 31);
                        for (int j = 0; j < sup; j += tp) {
                                for (int i = 0; i < tp && i + j < sup; i++) {
                                        isnp[j + i] |= ptn[i];
                                }
                        }
                }

                // 3,5,7
                // 2x+3=n
                int[] magic = { 0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13, 31, 22, 28, 18, 26, 10, 7, 12, 21, 17,
                                9, 6, 16, 5, 15, 14 };
                int h = n / 2;
                for (int i = 0; i < sup; i++) {
                        for (int j = ~isnp[i]; j != 0; j &= j - 1) {
                                int pp = i << 5 | magic[(j & -j) * 0x076be629 >>> 27];
                                int p = 2 * pp + 3;
                                if (p > n)
                                        break;
                                ret[pos++] = p;
                                if ((long) p * p > n)
                                        continue;
                                for (int q = (p * p - 3) / 2; q <= h; q += p)
                                        isnp[q >> 5] |= 1 << q;
                        }
                }

                return Arrays.copyOf(ret, pos);
        }

        
        public static final int[] NTTPrimes = {1053818881, 1051721729, 1045430273, 1012924417, 1007681537, 1004535809, 998244353, 985661441, 976224257, 975175681};
        public static final int[] NTTPrimitiveRoots = {7, 6, 3, 5, 3, 3, 3, 3, 3, 17};
//        public static final int[] NTTPrimes = {1012924417, 1004535809, 998244353, 985661441, 975175681, 962592769, 950009857, 943718401, 935329793, 924844033};
//        public static final int[] NTTPrimitiveRoots = {5, 3, 3, 3, 17, 7, 7, 7, 3, 5};
        
        public static long[] convoluteSimply(long[] a, long[] b, int P, int g)
        {
                int m = Math.max(2, Integer.highestOneBit(Math.max(a.length, b.length)-1)<<2);
                long[] fa = nttmb(a, m, false, P, g);
                long[] fb = a == b ? fa : nttmb(b, m, false, P, g);
                for(int i = 0;i < m;i++){
                        fa[i] = fa[i]*fb[i]%P;
                }
                return nttmb(fa, m, true, P, g);
        }
        
        public static long[] convolute(long[] a, long[] b)
        {
                int USE = 2;
                int m = Math.max(2, Integer.highestOneBit(Math.max(a.length, b.length)-1)<<2);
                long[][] fs = new long[USE][];
                for(int k = 0;k < USE;k++){
                        int P = NTTPrimes[k], g = NTTPrimitiveRoots[k];
                        long[] fa = nttmb(a, m, false, P, g);
                        long[] fb = a == b ? fa : nttmb(b, m, false, P, g);
                        for(int i = 0;i < m;i++){
                                fa[i] = fa[i]*fb[i]%P;
                        }
                        fs[k] = nttmb(fa, m, true, P, g);
                }
                
                int[] mods = Arrays.copyOf(NTTPrimes, USE);
                long[] gammas = garnerPrepare(mods);
                int[] buf = new int[USE];
                for(int i = 0;i < fs[0].length;i++){
                        for(int j = 0;j < USE;j++)buf[j] = (int)fs[j][i];
                        long[] res = garnerBatch(buf, mods, gammas);
                        long ret = 0;
                        for(int j = res.length-1;j >= 0;j--)ret = ret * mods[j] + res[j];
                        fs[0][i] = ret;
                }
                return fs[0];
        }
        
        public static long[] convolute(long[] a, long[] b, int USE, int mod)
        {
                int m = Math.max(2, Integer.highestOneBit(Math.max(a.length, b.length)-1)<<2);
                long[][] fs = new long[USE][];
                for(int k = 0;k < USE;k++){
                        int P = NTTPrimes[k], g = NTTPrimitiveRoots[k];
                        long[] fa = nttmb(a, m, false, P, g);
                        long[] fb = a == b ? fa : nttmb(b, m, false, P, g);
                        for(int i = 0;i < m;i++){
                                fa[i] = fa[i]*fb[i]%P;
                        }
                        fs[k] = nttmb(fa, m, true, P, g);
                }
                
                int[] mods = Arrays.copyOf(NTTPrimes, USE);
                long[] gammas = garnerPrepare(mods);
                int[] buf = new int[USE];
                for(int i = 0;i < fs[0].length;i++){
                        for(int j = 0;j < USE;j++)buf[j] = (int)fs[j][i];
                        long[] res = garnerBatch(buf, mods, gammas);
                        long ret = 0;
                        for(int j = res.length-1;j >= 0;j--)ret = (ret * mods[j] + res[j]) % mod;
                        fs[0][i] = ret;
                }
                return fs[0];
        }
        
        // static int[] wws = new int[270000]; // outer faster
        
        // Modifed Montgomery + Barrett
        private static long[] nttmb(long[] src, int n, boolean inverse, int P, int g)
        {
                long[] dst = Arrays.copyOf(src, n);
                
                int h = Integer.numberOfTrailingZeros(n);
                long K = Integer.highestOneBit(P)<<1;
                int H = Long.numberOfTrailingZeros(K)*2;
                long M = K*K/P;
                
                int[] wws = new int[1<<h-1];
                long dw = inverse ? pow(g, P-1-(P-1)/n, P) : pow(g, (P-1)/n, P);
                long w = (1L<<32)%P;
                for(int k = 0;k < 1<<h-1;k++){
                        wws[k] = (int)w;
                        w = modh(w*dw, M, H, P);
                }
                long J = invl(P, 1L<<32);
                for(int i = 0;i < h;i++){
                        for(int j = 0;j < 1<<i;j++){
                                for(int k = 0, s = j<<h-i, t = s|1<<h-i-1;k < 1<<h-i-1;k++,s++,t++){
                                        long u = (dst[s] - dst[t] + 2*P)*wws[k];
                                        dst[s] += dst[t];
                                        if(dst[s] >= 2*P)dst[s] -= 2*P;
//                                        long Q = (u&(1L<<32)-1)*J&(1L<<32)-1;
                                        long Q = (u<<32)*J>>>32;
                                        dst[t] = (u>>>32)-(Q*P>>>32)+P;
                                }
                        }
                        if(i < h-1){
                                for(int k = 0;k < 1<<h-i-2;k++)wws[k] = wws[k*2];
                        }
                }
                for(int i = 0;i < n;i++){
                        if(dst[i] >= P)dst[i] -= P;
                }
                for(int i = 0;i < n;i++){
                        int rev = Integer.reverse(i)>>>-h;
                        if(i < rev){
                                long d = dst[i]; dst[i] = dst[rev]; dst[rev] = d;
                        }
                }
                
                if(inverse){
                        long in = invl(n, P);
                        for(int i = 0;i < n;i++)dst[i] = modh(dst[i]*in, M, H, P);
                }
                
                return dst;
        }
        
        // Modified Shoup + Barrett
        private static long[] nttsb(long[] src, int n, boolean inverse, int P, int g)
        {
                long[] dst = Arrays.copyOf(src, n);
                
                int h = Integer.numberOfTrailingZeros(n);
                long K = Integer.highestOneBit(P)<<1;
                int H = Long.numberOfTrailingZeros(K)*2;
                long M = K*K/P;
                
                long dw = inverse ? pow(g, P-1-(P-1)/n, P) : pow(g, (P-1)/n, P);
                long[] wws = new long[1<<h-1];
                long[] ws = new long[1<<h-1];
                long w = 1;
                for(int k = 0;k < 1<<h-1;k++){
                        wws[k] = (w<<32)/P;
                        ws[k] = w;
                        w = modh(w*dw, M, H, P);
                }
                for(int i = 0;i < h;i++){
                        for(int j = 0;j < 1<<i;j++){
                                for(int k = 0, s = j<<h-i, t = s|1<<h-i-1;k < 1<<h-i-1;k++,s++,t++){
                                        long ndsts = dst[s] + dst[t];
                                        if(ndsts >= 2*P)ndsts -= 2*P;
                                        long T = dst[s] - dst[t] + 2*P;
                                        long Q = wws[k]*T>>>32;
                                        dst[s] = ndsts;
                                        dst[t] = ws[k]*T-Q*P&(1L<<32)-1;
                                }
                        }
//                        dw = dw * dw % P;
                        if(i < h-1){
                                for(int k = 0;k < 1<<h-i-2;k++){
                                        wws[k] = wws[k*2];
                                        ws[k] = ws[k*2];
                                }
                        }
                }
                for(int i = 0;i < n;i++){
                        if(dst[i] >= P)dst[i] -= P;
                }
                for(int i = 0;i < n;i++){
                        int rev = Integer.reverse(i)>>>-h;
                        if(i < rev){
                                long d = dst[i]; dst[i] = dst[rev]; dst[rev] = d;
                        }
                }
                
                if(inverse){
                        long in = invl(n, P);
                        for(int i = 0;i < n;i++){
                                dst[i] = modh(dst[i] * in, M, H, P);
                        }
                }
                
                return dst;
        }
        
        static final long mask = (1L<<31)-1;
        
        public static long modh(long a, long M, int h, int mod)
        {
                long r = a-((M*(a&mask)>>>31)+M*(a>>>31)>>>h-31)*mod;
                return r < mod ? r : r-mod;
        }
        
        private static long[] garnerPrepare(int[] m)
        {
                int n = m.length;
                assert n == m.length;
                if(n == 0)return new long[0];
                long[] gamma = new long[n];
                for(int k = 1;k < n;k++){
                        long prod = 1;
                        for(int i = 0;i < k;i++){
                                prod = prod * m[i] % m[k];
                        }
                        gamma[k] = invl(prod, m[k]);
                }
                return gamma;
        }
        
        private static long[] garnerBatch(int[] u, int[] m, long[] gamma)
        {
                int n = u.length;
                assert n == m.length;
                long[] v = new long[n];
                v[0] = u[0];
                for(int k = 1;k < n;k++){
                        long temp = v[k-1];
                        for(int j = k-2;j >= 0;j--){
                                temp = (temp * m[j] + v[j]) % m[k];
                        }
                        v[k] = (u[k] - temp) * gamma[k] % m[k];
                        if(v[k] < 0)v[k] += m[k];
                }
                return v;
        }
        
        private static long pow(long a, long n, long mod) {
                //                a %= mod;
                long ret = 1;
                int x = 63 - Long.numberOfLeadingZeros(n);
                for (; x >= 0; x--) {
                        ret = ret * ret % mod;
                        if (n << 63 - x < 0)
                                ret = ret * a % mod;
                }
                return ret;
        }
        
        private static long invl(long a, long mod) {
                long b = mod;
                long p = 1, q = 0;
                while (b > 0) {
                        long c = a / b;
                        long d;
                        d = a;
                        a = b;
                        b = d % b;
                        d = p;
                        p = q;
                        q = d - c * q;
                }
                return p < 0 ? p + mod : p;
        }


        void run() throws Exception {
                is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
                out = new PrintWriter(System.out);

                long s = System.currentTimeMillis();
                solve();
                out.flush();
                if (!INPUT.isEmpty())
                        tr(System.currentTimeMillis() - s + "ms");
        }

        public static void main(String[] args) throws Exception {
                new N25().run();
        }

        private byte[] inbuf = new byte[1024];
        public int lenbuf = 0, ptrbuf = 0;

        private int readByte() {
                if (lenbuf == -1)
                        throw new InputMismatchException();
                if (ptrbuf >= lenbuf) {
                        ptrbuf = 0;
                        try {
                                lenbuf = is.read(inbuf);
                        } catch (IOException e) {
                                throw new InputMismatchException();
                        }
                        if (lenbuf <= 0)
                                return -1;
                }
                return inbuf[ptrbuf++];
        }

        private boolean isSpaceChar(int c) {
                return !(c >= 33 && c <= 126);
        }

        private int skip() {
                int b;
                while ((b = readByte()) != -1 && isSpaceChar(b))
                        ;
                return b;
        }

        private double nd() {
                return Double.parseDouble(ns());
        }

        private char nc() {
                return (char) skip();
        }

        private String ns() {
                int b = skip();
                StringBuilder sb = new StringBuilder();
                while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b != '
                                                                        // ')
                        sb.appendCodePoint(b);
                        b = readByte();
                }
                return sb.toString();
        }

        private char[] ns(int n) {
                char[] buf = new char[n];
                int b = skip(), p = 0;
                while (p < n && !(isSpaceChar(b))) {
                        buf[p++] = (char) b;
                        b = readByte();
                }
                return n == p ? buf : Arrays.copyOf(buf, p);
        }

        private char[][] nm(int n, int m) {
                char[][] map = new char[n][];
                for (int i = 0; i < n; i++)
                        map[i] = ns(m);
                return map;
        }

        private int[] na(int n) {
                int[] a = new int[n];
                for (int i = 0; i < n; i++)
                        a[i] = ni();
                return a;
        }

        private int ni() {
                int num = 0, b;
                boolean minus = false;
                while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
                        ;
                if (b == '-') {
                        minus = true;
                        b = readByte();
                }

                while (true) {
                        if (b >= '0' && b <= '9') {
                                num = num * 10 + (b - '0');
                        } else {
                                return minus ? -num : num;
                        }
                        b = readByte();
                }
        }

        private long nl() {
                long num = 0;
                int b;
                boolean minus = false;
                while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
                        ;
                if (b == '-') {
                        minus = true;
                        b = readByte();
                }

                while (true) {
                        if (b >= '0' && b <= '9') {
                                num = num * 10 + (b - '0');
                        } else {
                                return minus ? -num : num;
                        }
                        b = readByte();
                }
        }

        private static void tr(Object... o) {
                System.out.println(Arrays.deepToString(o));
        }
}
# ユーザ名 問題 言語 状態 得点 提出日時
00271 uwi 0025 - のえるちゃん選び Java8 AC 15 18-03-23 02:00

セット

# セット 得点 Cases
1 ALL 15 / 15 *

テストケース

テストケース取得

ファイル名 状態 実行時間 メモリ使用量 #
random_01.txt AC 660 ms 42268 KB 1
random_02.txt AC 710 ms 42228 KB 1
random_03.txt AC 690 ms 45420 KB 1
random_04.txt AC 650 ms 44124 KB 1
random_05.txt AC 700 ms 46128 KB 1
random_06.txt AC 660 ms 45396 KB 1
random_07.txt AC 710 ms 45104 KB 1
random_08.txt AC 620 ms 45696 KB 1
random_09.txt AC 670 ms 44904 KB 1
random_10.txt AC 640 ms 45664 KB 1
random_11.txt AC 650 ms 44872 KB 1
random_12.txt AC 770 ms 45544 KB 1
random_13.txt AC 670 ms 45716 KB 1
random_14.txt AC 660 ms 45860 KB 1
random_15.txt AC 640 ms 42300 KB 1
random_16.txt AC 620 ms 45616 KB 1
random_17.txt AC 620 ms 45036 KB 1
sample_01.txt AC 580 ms 45804 KB 1
sample_02.txt AC 620 ms 45284 KB 1
sample_03.txt AC 610 ms 46108 KB 1