https://www.luogu.com.cn/problem/P2679

/*
CB Ntsc
*/

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define mp make_pair

#define rd read()
inline int read() {
    int xx = 0, ff = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9') {
        if (ch == '-')
            ff = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9') xx = xx * 10 + (ch - '0'), ch = getchar();
    return xx * ff;
}
inline void write(int out) {
    if (out < 0)
        putchar('-'), out = -out;
    if (out > 9)
        write(out / 10);
    putchar(out % 10 + '0');
}



const int N = 2e3 + 5;
const int M = 40;
const int INF = 1e9 + 5;
const int MOD = 1e9 + 7;


int sum[N][N];

int n,m,K,t,f[N][N]={1};
string a,b;


signed main(){
	n=rd;m=rd;K=rd;
	// cin>>n>>m>>K;
	// cerr<<f[2][1]<<endl;
	cin>>a>>b;

	// f[0][0]=1;
	for(int i=1;i<=n;i++){
		for(int j=m;j;j--){
			for(int k=K;k;k--){
				if(a[i-1]==b[j-1])sum[j][k]=(sum[j-1][k]+f[j-1][k-1])%MOD;
				else sum[j][k]=0;
				f[j][k]=(f[j][k]+sum[j][k])%MOD;
			}
		}
	}

	cout<<f[m][K];
	return 0;
}
/*
1
2 5 1 
0 0 1 
0 0 4 

*/

问题：

ideone和本地vscode均能过，提交后直接显示CE无CE信息，洛谷ide编译失败信息如下

Nothing is compiled: OUTPUT exceeds.