矩阵乘法板子

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#define int long long
#define ll long long 
using namespace std;
const ll mod=1000000007;
ll n,a,b,m,p;
struct re{
    int rec[501][501];
}ans,tem,org;
re tim(re x,re y){
    for(int i=1;i<=n;++i){
        for(int j=1;j<=m;++j){
            tem.rec[i][j]=0;
            for(int k=1;k<=p;++k){
                tem.rec[i][j]+=(x.rec[i][k]%mod)*(y.rec[k][j]%mod);
                tem.rec[i][j]%=mod;
            }
        }
    }
    return tem;
}
signed main(){
    scanf("%lld%lld%lld",&n,&p,&m);
    for(int i=1;i<=n;++i){
        for(int j=1;j<=p;++j){
            scanf("%lld",&org.rec[i][j]);
        }
    }
    for(int i=1;i<=p;++i){
        for(int j=1;j<=m;++j){
            scanf("%lld",&ans.rec[i][j]);
        }
    }
    ans=tim(org,ans);
    for(int i=1;i<=n;++i){
        for(int j=1;j<=m;++j){
            cout<<(ans.rec[i][j]+mod)%mod<<" ";
        }
        cout<<endl;
    }
    return 0;
}