zoj 2284 Inversion Number

#include <iostream>#include <cstdio>#include <string.h>using namespace std;int main(){    long long n, k, i, j, m[32][256];    memset(m, 0, sizeof(m));    for (n = 1; n <= 20; n++)        for (m[n][0] = 1, m[n][j = n * (n - 1) >> 1] = 1, k = 1; k < j; k++) for (i = k; i >= k - n + 1; i--)     m[n][k] += m[n - 1][i];    while (scanf("%lld %lld", &n, &k) != EOF && n)        printf("%lldn", m[n][k]);    return 0;}