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답안 #156100

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
156100 2019-10-03T10:41:27 Z EntityIT 전압 (JOI14_voltage) C++14
100 / 100
 225 ms 21240 KB 
#include<bits/stdc++.h>

using namespace std;

const int N = (int)1e5 + 5, M = N << 1, inf = (int)1e9 + 123;
int n, m, disc[N], low[N], curDisc, ans, nBadEdge, nBadEdgeTree[N];
bool parity[N], vis[N];
vector<int> gr[N], graph[N];

struct Edge {
    int u, v;
    bool used;
    Edge(int _u = 0, int _v = 0, bool _used = 0) : u(_u), v(_v), used(_used) {}
    int oth(int vertex) { return u ^ v ^ vertex; }
} edge[M];

void dfs(int u, int p) {
    disc[u] = low[u] = ++curDisc;
    parity[u] = parity[p] ^ 1;
    for (int id : gr[u]) if (!edge[id].used) {
        edge[id].used = 1;
        int v = edge[id].oth(u);
        if (!disc[v]) {
            graph[u].emplace_back(v);
            dfs(v, u);
            nBadEdgeTree[u] += nBadEdgeTree[v];
            low[u] = min(low[u], low[v]);
        }
        else {
            if (parity[u] == parity[v]) {
                ++nBadEdge;
                ++nBadEdgeTree[u]; --nBadEdgeTree[v];
            }
            else low[u] = min(low[u], disc[v]);
        }
    }
}

void solve(int u) {
    vis[u] = 1;
    for (int v : graph[u]) {
        solve(v);
        if (low[v] > disc[u] && nBadEdgeTree[v] == nBadEdge) ++ans;
    }
}

int main() {
//    freopen("input", "r", stdin);
    scanf(" %d %d", &n, &m);
    for (int i = 1; i <= m; ++i) {
        int u, v; scanf(" %d %d", &u, &v);
        edge[i] = Edge(u, v, 0);
        gr[u].emplace_back(i);
        gr[v].emplace_back(i);
    }

    for (int u = 1; u <= n; ++u) if (!disc[u]) dfs(u, 0);
    if (nBadEdge == 1) ++ans;
    for (int u = 1; u <= n; ++u) if (!vis[u]) solve(u);

    printf("%d", ans);

    return 0;
}

Compilation message

voltage.cpp: In function 'int main()':
voltage.cpp:49:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf(" %d %d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~~~
voltage.cpp:51:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         int u, v; scanf(" %d %d", &u, &v);
                   ~~~~~^~~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 10 ms 7544 KB Output is correct
2 Correct 10 ms 7416 KB Output is correct
3 Correct 8 ms 7416 KB Output is correct
4 Correct 8 ms 7416 KB Output is correct
5 Correct 9 ms 7544 KB Output is correct
6 Correct 9 ms 7544 KB Output is correct
7 Correct 9 ms 7416 KB Output is correct
8 Correct 9 ms 7416 KB Output is correct
9 Correct 8 ms 7416 KB Output is correct
10 Correct 9 ms 7416 KB Output is correct
11 Correct 9 ms 7544 KB Output is correct
12 Correct 8 ms 7544 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 58 ms 12564 KB Output is correct
2 Correct 114 ms 18680 KB Output is correct
3 Correct 64 ms 12588 KB Output is correct
4 Correct 115 ms 19836 KB Output is correct
5 Correct 15 ms 8312 KB Output is correct
6 Correct 98 ms 15676 KB Output is correct
7 Correct 117 ms 21240 KB Output is correct
8 Correct 125 ms 21224 KB Output is correct

Subtask #3
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 40 ms 12392 KB Output is correct
2 Correct 62 ms 21216 KB Output is correct
3 Correct 62 ms 21240 KB Output is correct
4 Correct 8 ms 7416 KB Output is correct
5 Correct 96 ms 15992 KB Output is correct
6 Correct 103 ms 13688 KB Output is correct
7 Correct 118 ms 17212 KB Output is correct
8 Correct 139 ms 19292 KB Output is correct
9 Correct 126 ms 18168 KB Output is correct
10 Correct 125 ms 16888 KB Output is correct
11 Correct 100 ms 13560 KB Output is correct
12 Correct 121 ms 15864 KB Output is correct

Subtask #4
45.0 / 45.0

# 결과 실행 시간 메모리 Grader output
1 Correct 66 ms 13132 KB Output is correct
2 Correct 90 ms 21188 KB Output is correct
3 Correct 10 ms 8312 KB Output is correct
4 Correct 123 ms 18020 KB Output is correct
5 Correct 133 ms 18908 KB Output is correct
6 Correct 133 ms 17628 KB Output is correct
7 Correct 190 ms 17912 KB Output is correct
8 Correct 190 ms 19192 KB Output is correct
9 Correct 179 ms 16908 KB Output is correct
10 Correct 176 ms 19040 KB Output is correct
11 Correct 183 ms 16632 KB Output is correct
12 Correct 181 ms 19060 KB Output is correct
13 Correct 160 ms 16112 KB Output is correct
14 Correct 167 ms 20116 KB Output is correct
15 Correct 199 ms 19192 KB Output is correct
16 Correct 225 ms 18544 KB Output is correct
17 Correct 175 ms 16036 KB Output is correct
18 Correct 165 ms 16096 KB Output is correct