Floyd Warshal 2, Candidates in no Shortest Path

#include <bits/stdc++.h>
// #include <atcoder/all>
using namespace std;
#define int long long
#define all(x) (x).begin(), (x).end()
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pair<int, int>> vpi;
typedef pair<int, int> pi;
#define f first
#define s second
#define pb push_back
#define endl "\n"
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
int dx[] = {-1, 0, 1, 0};
int dy[] = {0, 1, 0, -1};
const int mod1 = 1e9 + 7, mod2 = 998244353, INF = 2e18, N = 2e5 + 5, L = 19;
int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }
// -----------------------------------------------------------------------------
struct edge
{
    int u, v, wt;
};
void solve()
{
    int n, m;
    cin >> n >> m;
    vvi dist(n + 1, vi(n + 1, INF));
    vector<edge> edges;
    for (int i = 1; i <= n; i++)
    {
        dist[i][i] = 0;
    }
    for (int i = 0; i < m; i++)
    {
        int u, v, w;
        cin >> u >> v >> w;
        dist[u][v] = w;
        dist[v][u] = w;
        edges.pb({u, v, w});
    }
    for (int k = 1; k <= n; k++)
    {
        for (int i = 1; i <= n; i++)
        {
            for (int j = 1; j <= n; j++)
            {
                if (dist[i][k] < INF && dist[k][j] < INF)
                {
                    dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);
                }
            }
        }
    }
    int cnt = 0;
    for (auto [u, v, wt] : edges)
    {
        bool flag = false;
        for (int i = 1; i <= n; i++)
        {
            for (int j = 1; j <= n; j++)
            {
                int length = (dist[i][u] + wt + dist[v][j]);
                if (dist[i][j] == length)
                {
                    flag = true;
                    break;
                }
            }
            if (flag)
            {
                break;
            }
        }
        if (!flag)
        {
            cnt++;
        }
    }
    cout << (cnt) << endl;
    return;
}

signed main()
{
    // __START__;
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int t = 1;
    // cin >> t;
    while (t--)
    {
        solve();
    }
    // __END__;
    return 0;
}