Cod sursa(job #671581)

Utilizator dushmiMihai-Alexandru Dusmanu dushmi Data 31 ianuarie 2012 17:54:47
Problema Dreptunghiuri Scor 100
Compilator cpp Status done
Runda Lista lui wefgef Marime 1.35 kb
#include <cstdio>
#include <cmath>

int n, m, rad[160010], pp[160010];

void pregen() {
    for (int i = 0; i <= n * n; i++) {
        rad[i] = (int)sqrt(i);
        if (rad[i] * rad[i] == i)
            pp[i] = true;
    }
}

void solve() {
    long long rez = 0;

    int a, b, c, delta, v, s;

    for (int i = 1; i <= n; ++ i)
        for (int j = 1; j <= m; ++ j) {
            v = 1;

            for (int k = 1; k < j; ++ k ) {
                a = 1;
                b = - i;
                c = k * (j - k);

                delta = b * b - 4 * a * c;

                if (delta >= 0 && pp[delta]) {
                    s = - b - rad[delta];

                    if (s % (2 * a) == 0 && 1 <= s / (2 * a) && s / (2 * a) < i)
                        ++ v;

                    if (delta > 0) {
                        s = - b + rad[delta];

                        if (s % (2 * a) == 0 && 1 <= s / (2 * a) && s / (2 * a) < i)
                            ++ v;
                    }
                }
            }

            rez += (long long)(n - i + 1) * (m - j + 1) * v;
        }

    printf("%lld", rez);
}

int main() {
    freopen("dreptunghiuri.in", "r", stdin);
    freopen("dreptunghiuri.out", "w", stdout);

    scanf("%d%d", &n, &m);

    -- n;
    -- m;

    pregen();

    solve();

    return 0;
}