Submission #1046043

#	Time	Username	Problem	Language	Result	Execution time	Memory
1046043		becaido	Toy Train (IOI17_train)	C++17	0 / 100	5 ms	1884 KiB

train

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,popcnt,sse4,abm")
#include <bits/stdc++.h>
using namespace std;

#ifdef WAIMAI
#include "grader.cpp"
#else
#include "train.h"
#endif

#ifdef WAIMAI
#define debug(HEHE...) cout << "[" << #HEHE << "] : ", dout(HEHE)
void dout() {cout << '\n';}
template<typename T, typename...U>
void dout(T t, U...u) {cout << t << (sizeof...(u) ? ", " : ""), dout(u...);}
#else
#define debug(...) 7122
#endif

#define ll long long
#define Waimai ios::sync_with_stdio(false), cin.tie(0)
#define FOR(x,a,b) for (int x = a, I = b; x <= I; x++)
#define pb emplace_back
#define F first
#define S second

const int SIZE = 5005;

int n, m;
int sz[SIZE];
vector<int> adj[SIZE], rev[SIZE];
bool alice[SIZE], is[SIZE], self[SIZE], dp[SIZE], vs[SIZE];

struct SCC {
    int n, dfcnt = 0, sccnt = 0;
    vector<int> dfn, low, scc, st, ist;
    vector<vector<int>> scc_adj;
    SCC() {}
    SCC(int n) : n(n) {
        dfn = low = scc = ist = vector<int>(n + 1, 0);
        scc_adj = vector<vector<int>>(n + 1, vector<int>());
    }
    void tarjan(int pos) {
        dfn[pos] = low[pos] = ++dfcnt;
        st.emplace_back(pos);
        ist[pos] = 1;
        for (int np : adj[pos]) {
            if (dfn[np] == 0) {
                tarjan(np);
                low[pos] = min(low[pos], low[np]);
            } else if (ist[np] == 1) {
                low[pos] = min(low[pos], dfn[np]);
            }
        }
        if (dfn[pos] == low[pos]) {
            sccnt++;
            while (1) {
                int x = st.back();
                ist[x] = 0;
                scc[x] = sccnt;
                st.pop_back();
                if (x == pos) {
                    break;
                }
            }
        }
    }
    void work() {
        for (int i = 1; i <= n; i++) {
            if (dfn[i] == 0) {
                tarjan(i);
            }
        }
    }
    void build_adj() {
        for (int i = 1; i <= n; i++) {
            for (int j : adj[i]) {
                if (scc[i] != scc[j]) {
                    scc_adj[scc[i]].emplace_back(scc[j]);
                }
            }
        }
    }
    vector<int> cal() {
        FOR (i, 1, n) sz[scc[i]]++;
        queue<int> q;
        FOR (i, 1, n) if (is[i] == 0 && (sz[scc[i]] > 1 || self[i])) vs[i] = 1, q.push(i);
        while (q.size()) {
            int pos = q.front();
            q.pop();
            for (int np : rev[pos]) if (vs[np] == 0) {
                vs[np] = 1;
                q.push(np);
            }
        }
        vector<int> ans;
        FOR (i, 1, n) ans.pb(!vs[scc[i]]);
        return ans;
    }
} g;

vector<int> who_wins(vector<int> a_, vector<int> r_, vector<int> u_, vector<int> v_) {
    n = a_.size();
    m = u_.size();
    FOR (i, 1, n) {
        alice[i] = a_[i - 1];
        is[i] = r_[i - 1];
        adj[i].clear();
        rev[i].clear();
        self[i] = dp[i] = vs[i] = sz[i] = 0;
    }
    FOR (i, 0, m - 1) {
        u_[i]++, v_[i]++;
        if (u_[i] == v_[i]) self[u_[i]] = 1;
        else {
            if (is[u_[i]] == 0 && is[v_[i]] == 0) adj[u_[i]].pb(v_[i]);
            rev[v_[i]].pb(u_[i]);
        }
    }
    g = SCC(n);
    g.work();
    g.build_adj();
    return g.cal();
}

/*
in1
2 4
0 1
1 0
0 0
0 1
1 0
1 1
out1
1 1
*/

Compilation message (stderr)

train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:111:41: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  111 |         self[i] = dp[i] = vs[i] = sz[i] = 0;
      |                                   ~~~~~~^~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 11
• Subtask 4: 0 / 11
• Subtask 5: 0 / 12
• Subtask 6: 0 / 51