AC on #6，其他WA求助

应该不是tarjan的问题啊。。 我用的是map存储答案

测评记录

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

const int M = 1e5 + 10, N = 1e4 + 10;
using tr = map<int, int>::iterator;
// struct Edge
// {
//  int to, next;
// } e[M];
// int cnt, head[M];
// void add(int x, int y)
// {
//  ++cnt;
//  e[cnt] = {y, head[x]};
//  head[x] = cnt;
// }

int dfn[N], low[N], times, tot;
map<int, int> mm;
vector<int> v[N], ans[N];
stack<int> s;
bool b[N];
void tarjan(int x)
{
    dfn[x] = low[x] = ++times;
    s.push(x);
    b[x] = true;
    int to;
    for (int j = 0; j < v[x].size(); ++j)
    {
        to = v[x][j];
        // to = e[j].to;
        if (!dfn[to])
        {
            tarjan(to);
            low[x] = min(low[x], low[to]);
        }
        else if (b[to])
            low[x] = min(low[x], dfn[to]);
    }
    if (dfn[x] == low[x])
    {
        ++tot;
        mm[x] = tot;
        while (x != s.top())
        {
            ans[tot].push_back(s.top());
            b[s.top()] = false;
            s.pop();
        }
        ans[tot].push_back(s.top());
        b[s.top()] = false;
        s.pop();
    }
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int n, m, i, j, x, y;
    cin >> n >> m;
    for (j = 1; j <= m; ++j)
    {
        cin >> x >> y;
        if (x == y)
            continue;
        v[x].push_back(y);
        // add(x, y);
    }
    for (j = 1; j <= n; ++j)
    {
        if (dfn[j] == 0)
        {
            tarjan(j);
        }
    }
    // for (i = 1; i <= n; ++i)
    // {
    //  cout << i << "dfn:" << dfn[i] << "low:" << low[i] << '\n';
    // }
    for (tr i = mm.begin(); i != mm.end(); ++i)
    {
        sort(ans[i->second].begin(), ans[i->second].end());
    }
    cout << tot << '\n';
    for (tr i = mm.begin(); i != mm.end(); ++i)
    {
        for (j = 0; j < ans[i->second].size(); ++j)
        {
            cout << ans[i->second][j] << ' ';
        }
        cout << '\n';
    }
    return 0;
}