oj.uz

답안 #1073742

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1073742 2024-08-24T19:46:03 Z andrewp 꿈 (IOI13_dreaming) C++14
14 / 100
 31 ms 14804 KB 
//Dedicated to my love, ivaziva 
#include <bits/stdc++.h> 
#include "dreaming.h"
using namespace std; 

using pii = pair<int, int>;
using ll = int64_t;

#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define dbg(x) cerr << #x << ": " << x << '\n';

constexpr int mxN = 1e5 + 20;
vector<pii> g[mxN]; 
int dist1[mxN], dist2[mxN], par[mxN];  
bool vis[mxN];
vector<int> vec, dijametar;

void dfs(int x, int p) {  
    vis[x] = true;   
    vec.push_back(x);  
    for (auto ptr: g[x]) {
        if (ptr.first != p) {  
            dist1[ptr.first] = dist1[x] + ptr.second;
            dfs(ptr.first, x);  
        }
    }
}  
void dfs2(int x, int p) {   
    par[x] = p;
    for (auto ptr: g[x]) {
        if (ptr.first != p) {  
            dist2[ptr.first] = dist2[x] + ptr.second;
            dfs2(ptr.first, x);  
        }
    }
}  

int travelTime(int N, int M, int L, int* A, int* B, int* T) {
    for (int i = 0; i < M; i++) {
        g[A[i]].push_back({B[i], T[i]});
        g[B[i]].push_back({A[i], T[i]});
    } 
    for (int i = 0; i < N; i++) {
        dist1[i] = 0, dist2[i] = 0;
        vis[i] = false;
    }
    vector<int> diams, anss;
    for (int i = 0; i < N; i++) {
        if (!vis[i]) { 
            dijametar.clear();
            vec.clear(); 
            dfs(i, -1); 
            int mx = 0, root = 0; 
            for (int x: vec) { 
                if (mx < dist1[x]) {
                    root = x;
                    mx = dist1[x];
                }
            }  
            dfs2(root, -1);
            int diamend = 0;
            mx = 0; 
            for (int x: vec) {
                if (mx < dist2[x]) {
                    mx = dist2[x];
                    diamend = x;
                }
            }    
            diams.push_back(mx);
            while (diamend != -1) {  
                dijametar.push_back(diamend); 
                diamend = par[diamend];
            }  
            int diff = (int)(2e9), cen = 0, krc = 0;
            for (int x: dijametar) {
                if (diff > abs(dist2[x] - mx / 2)) {
                    diff = abs(dist2[x] - mx / 2);
                    cen = x;
                    krc = dist2[x];
                }
            }
            anss.push_back(max(krc, mx - krc));
        } 
    }     
    int ans = max(diams[0], diams[1]);
    ans = max(ans, anss[0] + anss[1] + L); 
    return ans;
}

/*int32_t main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    cout.tie(nullptr); cerr.tie(nullptr);

    int n, m, l;
    cin >> n >> m >> l;
    int a[m], b[m], t[m];
    for (int i = 0; i < m; i++) {
        cin >> a[i] >> b[i] >> t[i];
    }
    int ans = travelTime(n, m, l, a, b, t); 
    cout << ans << '\n';
    return 0;
}*/
/*
12 8 2
0 8 4
8 2 2
2 7 4
5 11 3
5 1 7
1 3 1
1 9 5
10 6 3 
*/

Compilation message

dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:75:36: warning: variable 'cen' set but not used [-Wunused-but-set-variable]
   75 |             int diff = (int)(2e9), cen = 0, krc = 0;
      |                                    ^~~

Subtask #1
14.0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 14804 KB Output is correct
2 Correct 28 ms 14784 KB Output is correct
3 Correct 20 ms 11368 KB Output is correct
4 Correct 5 ms 6492 KB Output is correct
5 Correct 4 ms 5720 KB Output is correct
6 Correct 9 ms 7260 KB Output is correct
7 Correct 1 ms 4956 KB Output is correct
8 Correct 15 ms 8280 KB Output is correct
9 Correct 20 ms 9696 KB Output is correct
10 Correct 2 ms 4952 KB Output is correct
11 Correct 29 ms 10876 KB Output is correct
12 Correct 31 ms 13012 KB Output is correct
13 Correct 1 ms 4952 KB Output is correct

Subtask #2
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 1 ms 4956 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 14804 KB Output is correct
2 Correct 28 ms 14784 KB Output is correct
3 Correct 20 ms 11368 KB Output is correct
4 Correct 5 ms 6492 KB Output is correct
5 Correct 4 ms 5720 KB Output is correct
6 Correct 9 ms 7260 KB Output is correct
7 Correct 1 ms 4956 KB Output is correct
8 Correct 15 ms 8280 KB Output is correct
9 Correct 20 ms 9696 KB Output is correct
10 Correct 2 ms 4952 KB Output is correct
11 Correct 29 ms 10876 KB Output is correct
12 Correct 31 ms 13012 KB Output is correct
13 Correct 1 ms 4952 KB Output is correct
14 Incorrect 1 ms 4956 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #4
0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 20 ms 7604 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 1 ms 4956 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 14804 KB Output is correct
2 Correct 28 ms 14784 KB Output is correct
3 Correct 20 ms 11368 KB Output is correct
4 Correct 5 ms 6492 KB Output is correct
5 Correct 4 ms 5720 KB Output is correct
6 Correct 9 ms 7260 KB Output is correct
7 Correct 1 ms 4956 KB Output is correct
8 Correct 15 ms 8280 KB Output is correct
9 Correct 20 ms 9696 KB Output is correct
10 Correct 2 ms 4952 KB Output is correct
11 Correct 29 ms 10876 KB Output is correct
12 Correct 31 ms 13012 KB Output is correct
13 Correct 1 ms 4952 KB Output is correct
14 Incorrect 1 ms 4956 KB Output isn't correct
15 Halted 0 ms 0 KB -