C++问题-N个学生组成M个队伍

Question

问题链接：https://noi.vip/problem/1061

Answer 1

#include <stdio.h>
#include <stdlib.h>
long long mod = 1e9+9;
long long arr[3005][3005];
int main() {
    long long people, group;
    scanf("%lld %lld",&people,&group);
    arr[1][1] = 1;
    for(int i = 2 ; i <= people; i ++) {
        for(int j = 1; j <= i; j++) {
            arr[i][j] = arr[i-1][j-1]+j*arr[i-1][j];//单独放最后一个+最后一任选
            if(arr[i][j]>mod)arr[i][j] %= mod;
        }
    }
    printf("%lld",arr[people][group]);
}