sub1+2都是wa，sub3一片re+wa一个，sub4后面几个点过了，前6个点是re。 代码：

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

const int N = 2e5 + 10;
// const int N = 11;

int t, n;
long long anss, ans[N];
int dfn[N], low[N], tot;
int stk[N], instk[N], top;
int cnt, scc[N], siz[N], sum[N];
vector<vector<int> > e(N), nw(N);

void tarjan(int u) {
    dfn[u] = low[u] = ++tot;
    stk[++top] = u, instk[u] = 1;
    for (int v : e[u]) {
        if (!dfn[v]) {
            tarjan(v);
            low[u] = min(low[u], low[v]);
        } else if (instk[v]) {
            low[u] = min(low[u], dfn[v]);
        }
    }
    if (dfn[u] == low[u]) {
        ++cnt;
        int v;
        do {
            v = stk[top--];
            instk[v] = 0;
            scc[v] = cnt;
            siz[cnt]++, sum[cnt]++;
        } while (u != v);
    }
}

void process() {
    for (int u = 1; u <= n; u++) {
        for (int v : e[u]) {
            if (scc[u] == scc[v])
                continue;
            nw[scc[u]].push_back(scc[v]);
        }
    }
    for (int i = cnt; i; i--) {
        bool flag = 1;
        for (int j : nw[i]) {
            flag = 0;
            ans[j] += ans[i] + 1LL * sum[i] * siz[j];
            sum[j] += sum[i];
        }

        if (flag)
            anss += ans[i];
    }
}

int main() {
    cin >> t;
    while (t--) {
        cin >> n;
        memset(ans, 0, 8 * n);
        memset(dfn, 0, 4 * n);
        memset(low, 0, 4 * n);
        memset(scc, 0, 4 * n);
        memset(siz, 0, 4 * n);
        memset(sum, 0, 4 * n);
        memset(instk, 0, 4 * n);
        memset(stk, 0, 4 * n);
        e.clear(), nw.clear();
        e.resize(n), nw.resize(n);

        tot = top = cnt = anss = 0;
        for (int i = 1; i < n; i++) {
            char chr = getchar();
            if (chr == ' ' || chr == '\n')
                chr = getchar();
            if (chr == '<') {
                e[i].push_back(i + 1);
            } else if (chr == '>') {
                e[i + 1].push_back(i);
            } else {
                e[i].push_back(i + 1);
                e[i + 1].push_back(i);
            }
        }
        for (int i = 1; i <= n; i++) {
            if (!dfn[i])
                tarjan(i);
        }
        process();
        cout << anss << '\n';
    }
    return 0;
}