1 #include <cstdio> 2 #include <cstring> 3 #include <iostream> 4 using namespace std; 5 #define ll long long 6 const int MOD = 1000007; 7 const int maxk = 500; 8 ll C[maxk + 2][maxk + 2]; 9 // 线性算法，可以加取模10 void get_C(){11     memset(C,0,sizeof C);12     C[0][0] = 1;13     for(int i = 0 ; i <= maxk ; i++){14         C[i][0] = C[i][i] = 1;15         for(int j = 1 ; j < i ; j++)16             C[i][j] = (C[i - 1][j] + C[i - 1][j - 1]);17     }18 }19 // 直接计算，不要随便取模，计算量过大时会有误差20 long long cal_C(long long n,long long m){21     double ans = 1;22     for(int i = 0 ; i < m ; i++) ans *= n - i;23     for(int i = 0 ; i < m ; i++) ans /= i + 1;24     return (long long)(ans + 0.5);25 }26 int main(){27     get_C();28     for(int i = 0 ; i < 225 ; i++)29         for(int j = 0 ; j <= i && j < 10 ; j++)if(C[i][j] != cal_C(i,j))30             printf("%d %d :%lld,%lld\n",i,j,C[i][j],cal_C(i,j));31     return 0;32 }