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답안 #524869

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
524869 2022-02-10T07:31:01 Z qwerasdfzxcl Mountains and Valleys (CCO20_day1problem3) C++14
3 / 25
 14 ms 12748 KB 
#include <bits/stdc++.h>

typedef long long ll;
using namespace std;
struct Edge{
    int v, w, i;
    Edge(){}
    Edge(int _v, int _w, int _i): v(_v), w(_w), i(_i) {}
};
vector<Edge> adj[500500];
int on[2002000], W[2002000], dist[500500];
vector<Edge> E;

vector<int> P;
bool dfs0(int s, int e, int pa = -1){
    if (s==e) return 1;
    for (auto &v:adj[s]) if (v.v!=pa && on[v.i]){
        P.push_back(v.i);
        if (dfs0(v.v, e, s)) return 1;
        P.pop_back();
    }
    return 0;
}

void dfs(int s, int pa = -1, int w = 0){
    if (pa==-1) dist[s] = 0;
    else dist[s] = dist[pa] + w;
    for (auto &v:adj[s]) if (v.v!=pa && on[v.i]) dfs(v.v, s, v.w);
}

int cur = 0, ans = 1e9, m;
void calc(int n){
    dfs(0);
    dfs(max_element(dist, dist+n)-dist);

    ans = min(ans, cur*2 - *max_element(dist, dist+n));

    //printf("cur: %d, ans = %d\n", cur, cur*2 - *max_element(dist, dist+n));
    //for (int i=1;i<=m;i++) printf("%d ", on[i]);
    //printf("\n");
}

int main(){
    int n;
    scanf("%d %d", &n, &m);
    for (int i=1;i<=m;i++){
        int x, y, z;
        scanf("%d %d %d", &x, &y, &z);
        adj[x].emplace_back(y, z, i);
        adj[y].emplace_back(x, z, i);
        W[i] = z;

        if (z==1) on[i] = 1, cur++;
        else E.emplace_back(x, y, i);
    }

    calc(n);
    if (n>500) {printf("%d\n", ans); return 0;}

    for (auto &e:E){
        P.clear();
        assert(dfs0(e.v, e.w));
        //printf("%d %d: ", e.v, e.w);
        //for (auto &x:P) printf("%d ", x);
        //printf("\n");
        if ((int)P.size()<=W[e.i]) continue;

        on[e.i] = 1, cur += W[e.i];

        for (auto &x:P){
            on[x] = 0, cur -= W[x];
            calc(n);
            on[x] = 1, cur += W[x];
        }

        on[e.i] = 0, cur -= W[e.i];
    }

    printf("%d\n", ans);
    return 0;
}

Compilation message

Main.cpp: In function 'int main()':
Main.cpp:45:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
Main.cpp:48:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |         scanf("%d %d %d", &x, &y, &z);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
1.0 / 1.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11984 KB Output is correct
2 Correct 7 ms 12040 KB Output is correct
3 Correct 6 ms 11980 KB Output is correct
4 Correct 6 ms 12016 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 7 ms 11980 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11980 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 9 ms 11980 KB Output is correct
13 Correct 7 ms 12024 KB Output is correct
14 Correct 6 ms 11980 KB Output is correct
15 Correct 8 ms 11980 KB Output is correct

Subtask #2
0.0 / 2.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11984 KB Output is correct
2 Correct 7 ms 12040 KB Output is correct
3 Correct 6 ms 11980 KB Output is correct
4 Correct 6 ms 12016 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 7 ms 11980 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11980 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 9 ms 11980 KB Output is correct
13 Correct 7 ms 12024 KB Output is correct
14 Correct 6 ms 11980 KB Output is correct
15 Correct 8 ms 11980 KB Output is correct
16 Correct 6 ms 11980 KB Output is correct
17 Correct 6 ms 12052 KB Output is correct
18 Incorrect 6 ms 12068 KB Output isn't correct
19 Halted 0 ms 0 KB -

Subtask #3
2.0 / 2.0

# 결과 실행 시간 메모리 Grader output
1 Correct 10 ms 12748 KB Output is correct
2 Correct 10 ms 12748 KB Output is correct
3 Correct 10 ms 12708 KB Output is correct
4 Correct 11 ms 12620 KB Output is correct
5 Correct 10 ms 12620 KB Output is correct
6 Correct 11 ms 12592 KB Output is correct
7 Correct 11 ms 12748 KB Output is correct
8 Correct 10 ms 12748 KB Output is correct
9 Correct 10 ms 12728 KB Output is correct
10 Correct 10 ms 12700 KB Output is correct
11 Correct 10 ms 12620 KB Output is correct
12 Correct 14 ms 12636 KB Output is correct
13 Correct 11 ms 12748 KB Output is correct
14 Correct 11 ms 12720 KB Output is correct

Subtask #4
0.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11984 KB Output is correct
2 Correct 7 ms 12040 KB Output is correct
3 Correct 6 ms 11980 KB Output is correct
4 Correct 6 ms 12016 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 7 ms 11980 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11980 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 9 ms 11980 KB Output is correct
13 Correct 7 ms 12024 KB Output is correct
14 Correct 6 ms 11980 KB Output is correct
15 Correct 8 ms 11980 KB Output is correct
16 Correct 6 ms 11980 KB Output is correct
17 Correct 6 ms 12052 KB Output is correct
18 Incorrect 6 ms 12068 KB Output isn't correct
19 Halted 0 ms 0 KB -

Subtask #5
0.0 / 2.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11984 KB Output is correct
2 Correct 7 ms 12040 KB Output is correct
3 Correct 6 ms 11980 KB Output is correct
4 Correct 6 ms 12016 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 7 ms 11980 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11980 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 9 ms 11980 KB Output is correct
13 Correct 7 ms 12024 KB Output is correct
14 Correct 6 ms 11980 KB Output is correct
15 Correct 8 ms 11980 KB Output is correct
16 Correct 6 ms 11980 KB Output is correct
17 Correct 6 ms 12052 KB Output is correct
18 Incorrect 6 ms 12068 KB Output isn't correct
19 Halted 0 ms 0 KB -

Subtask #6
0.0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11984 KB Output is correct
2 Correct 7 ms 12040 KB Output is correct
3 Correct 6 ms 11980 KB Output is correct
4 Correct 6 ms 12016 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 7 ms 11980 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11980 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 9 ms 11980 KB Output is correct
13 Correct 7 ms 12024 KB Output is correct
14 Correct 6 ms 11980 KB Output is correct
15 Correct 8 ms 11980 KB Output is correct
16 Correct 6 ms 11980 KB Output is correct
17 Correct 6 ms 12052 KB Output is correct
18 Incorrect 6 ms 12068 KB Output isn't correct
19 Halted 0 ms 0 KB -

Subtask #7
0.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11984 KB Output is correct
2 Correct 7 ms 12040 KB Output is correct
3 Correct 6 ms 11980 KB Output is correct
4 Correct 6 ms 12016 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 7 ms 11980 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11980 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 9 ms 11980 KB Output is correct
13 Correct 7 ms 12024 KB Output is correct
14 Correct 6 ms 11980 KB Output is correct
15 Correct 8 ms 11980 KB Output is correct
16 Correct 6 ms 11980 KB Output is correct
17 Correct 6 ms 12052 KB Output is correct
18 Incorrect 6 ms 12068 KB Output isn't correct
19 Halted 0 ms 0 KB -

Subtask #8
0.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11984 KB Output is correct
2 Correct 7 ms 12040 KB Output is correct
3 Correct 6 ms 11980 KB Output is correct
4 Correct 6 ms 12016 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 7 ms 11980 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11980 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 9 ms 11980 KB Output is correct
13 Correct 7 ms 12024 KB Output is correct
14 Correct 6 ms 11980 KB Output is correct
15 Correct 8 ms 11980 KB Output is correct
16 Correct 6 ms 11980 KB Output is correct
17 Correct 6 ms 12052 KB Output is correct
18 Incorrect 6 ms 12068 KB Output isn't correct
19 Halted 0 ms 0 KB -