求助求助，为什么会re

#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 210,INF = 1e9;
int n, m;
int d[N][N];
void floyd() {
for (int k = 1; k <= n; k ++) {
for (int i = 1; i <= n; i ++) {
for (int j = 1; j <= n; j ++) {
d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
}
}
}
}
int main () {
scanf("%d%d%d", &n, &m);
for (int i = 1; i <= n; i ++) {
for (int j = 1; j <= n; j ++) {
if(i == j) {
d[i][j] = 0;
} else {
d[i][j] = INF;
}
}
}
while (m --) {
int a, b, w;
scanf("%d%d%d", &a, &b, &w);
d[a][b] = min(d[a][b], w);
}
floyd();
for(int i = 1;i<=n;i++)
{
for(int j = 1;i<=n;i++)
{
printf("%d ",d[i][j]);
}
printf("\n");
}
return 0;
}