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Submission #524852

# Submission time Handle Problem Language Result Execution time Memory
524852 2022-02-10T06:54:48 Z qwerasdfzxcl Mountains and Valleys (CCO20_day1problem3) C++14
3 / 25
 14 ms 12768 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;
}

int cnt;
void dfs(int s, int pa = -1, int w = 0){
    cnt++;
    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;
void calc(int n){
    cnt = 0;
    dfs(0);
    assert(cnt==n);

    cnt = 0;
    dfs(max_element(dist, dist+n)-dist);
    assert(cnt==n);

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

int main(){
    int n, m;
    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();
        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:48:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
Main.cpp:51:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         scanf("%d %d %d", &x, &y, &z);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 11980 KB Output is correct
2 Correct 7 ms 11980 KB Output is correct
3 Correct 6 ms 12076 KB Output is correct
4 Correct 8 ms 12060 KB Output is correct
5 Correct 6 ms 12004 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 6 ms 11956 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 6 ms 11980 KB Output is correct
13 Correct 6 ms 12072 KB Output is correct
14 Correct 7 ms 11980 KB Output is correct
15 Correct 6 ms 11980 KB Output is correct

Subtask #2
0.0 / 2.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 11980 KB Output is correct
2 Correct 7 ms 11980 KB Output is correct
3 Correct 6 ms 12076 KB Output is correct
4 Correct 8 ms 12060 KB Output is correct
5 Correct 6 ms 12004 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 6 ms 11956 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 6 ms 11980 KB Output is correct
13 Correct 6 ms 12072 KB Output is correct
14 Correct 7 ms 11980 KB Output is correct
15 Correct 6 ms 11980 KB Output is correct
16 Correct 8 ms 11980 KB Output is correct
17 Correct 6 ms 11980 KB Output is correct
18 Incorrect 7 ms 12108 KB Output isn't correct
19 Halted 0 ms 0 KB -

Subtask #3
2.0 / 2.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 12748 KB Output is correct
2 Correct 12 ms 12768 KB Output is correct
3 Correct 10 ms 12620 KB Output is correct
4 Correct 12 ms 12616 KB Output is correct
5 Correct 10 ms 12620 KB Output is correct
6 Correct 10 ms 12620 KB Output is correct
7 Correct 12 ms 12760 KB Output is correct
8 Correct 10 ms 12620 KB Output is correct
9 Correct 14 ms 12748 KB Output is correct
10 Correct 13 ms 12644 KB Output is correct
11 Correct 10 ms 12708 KB Output is correct
12 Correct 10 ms 12688 KB Output is correct
13 Correct 10 ms 12728 KB Output is correct
14 Correct 10 ms 12696 KB Output is correct

Subtask #4
0.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 11980 KB Output is correct
2 Correct 7 ms 11980 KB Output is correct
3 Correct 6 ms 12076 KB Output is correct
4 Correct 8 ms 12060 KB Output is correct
5 Correct 6 ms 12004 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 6 ms 11956 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 6 ms 11980 KB Output is correct
13 Correct 6 ms 12072 KB Output is correct
14 Correct 7 ms 11980 KB Output is correct
15 Correct 6 ms 11980 KB Output is correct
16 Correct 8 ms 11980 KB Output is correct
17 Correct 6 ms 11980 KB Output is correct
18 Incorrect 7 ms 12108 KB Output isn't correct
19 Halted 0 ms 0 KB -

Subtask #5
0.0 / 2.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 11980 KB Output is correct
2 Correct 7 ms 11980 KB Output is correct
3 Correct 6 ms 12076 KB Output is correct
4 Correct 8 ms 12060 KB Output is correct
5 Correct 6 ms 12004 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 6 ms 11956 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 6 ms 11980 KB Output is correct
13 Correct 6 ms 12072 KB Output is correct
14 Correct 7 ms 11980 KB Output is correct
15 Correct 6 ms 11980 KB Output is correct
16 Correct 8 ms 11980 KB Output is correct
17 Correct 6 ms 11980 KB Output is correct
18 Incorrect 7 ms 12108 KB Output isn't correct
19 Halted 0 ms 0 KB -

Subtask #6
0.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 11980 KB Output is correct
2 Correct 7 ms 11980 KB Output is correct
3 Correct 6 ms 12076 KB Output is correct
4 Correct 8 ms 12060 KB Output is correct
5 Correct 6 ms 12004 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 6 ms 11956 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 6 ms 11980 KB Output is correct
13 Correct 6 ms 12072 KB Output is correct
14 Correct 7 ms 11980 KB Output is correct
15 Correct 6 ms 11980 KB Output is correct
16 Correct 8 ms 11980 KB Output is correct
17 Correct 6 ms 11980 KB Output is correct
18 Incorrect 7 ms 12108 KB Output isn't correct
19 Halted 0 ms 0 KB -

Subtask #7
0.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 11980 KB Output is correct
2 Correct 7 ms 11980 KB Output is correct
3 Correct 6 ms 12076 KB Output is correct
4 Correct 8 ms 12060 KB Output is correct
5 Correct 6 ms 12004 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 6 ms 11956 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 6 ms 11980 KB Output is correct
13 Correct 6 ms 12072 KB Output is correct
14 Correct 7 ms 11980 KB Output is correct
15 Correct 6 ms 11980 KB Output is correct
16 Correct 8 ms 11980 KB Output is correct
17 Correct 6 ms 11980 KB Output is correct
18 Incorrect 7 ms 12108 KB Output isn't correct
19 Halted 0 ms 0 KB -

Subtask #8
0.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 11980 KB Output is correct
2 Correct 7 ms 11980 KB Output is correct
3 Correct 6 ms 12076 KB Output is correct
4 Correct 8 ms 12060 KB Output is correct
5 Correct 6 ms 12004 KB Output is correct
6 Correct 6 ms 11980 KB Output is correct
7 Correct 6 ms 11956 KB Output is correct
8 Correct 6 ms 11980 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 6 ms 11980 KB Output is correct
11 Correct 6 ms 11980 KB Output is correct
12 Correct 6 ms 11980 KB Output is correct
13 Correct 6 ms 12072 KB Output is correct
14 Correct 7 ms 11980 KB Output is correct
15 Correct 6 ms 11980 KB Output is correct
16 Correct 8 ms 11980 KB Output is correct
17 Correct 6 ms 11980 KB Output is correct
18 Incorrect 7 ms 12108 KB Output isn't correct
19 Halted 0 ms 0 KB -