PROG-1112: ลำดับสลับสับสน (inversion)

#include <bits/stdc++.h>
using namespace std;

const int INF = 1e9;

int dp1[10001],dp2[10001];

int main(){

    int n,k;
    scanf("%d%d",&n,&k);

    for(int i=0;i<=n;i++){
        for(int j=0;j<=k;j++){
            if(j == 0) dp2[j] = 1;
            if(j == 0 or i == 0) continue;
            for(int x=0;x<i;x++){
                if(j-x >=0 ) dp2[j] += dp1[j-x];
            }
            dp2[j] = dp2[j]%2012;
        }
        for(int j=0;j<=k;j++) {
            dp1[j] = dp2[j];
            dp2[j] = 0;
        }
    }

    printf("%d",dp1[k]);

    return 0;
}