oj.uz

답안 #313819

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
313819 2020-10-17T06:22:52 Z BeanZ Dynamite (POI11_dyn) C++14
100 / 100
 1997 ms 36984 KB 
// I_Love_LPL
#include <bits/stdc++.h>
using namespace std;

#define ll int
#define endl '\n'
const int N = 3e5 + 5;
ll cnt = 0, mid;
ll dp[N], hp[N], a[N], farcry[N];
vector<ll> node[N];
void dfs(ll u, ll p){
    hp[u] = 0;
    for (auto j : node[u]){
        if (j == p) continue;
        dfs(j, u);
        farcry[u] = min(farcry[u], farcry[j] + 1);
    }
    if (a[u] == 1 && farcry[u] > mid) hp[u] = 1, dp[u] = 0;
    for (auto j : node[u]){
        if (j == p) continue;
        if (hp[j]){
            if ((farcry[u] + dp[j] + 1) <= mid) continue;
            else dp[u] = max(dp[u], dp[j] + 1), hp[u] = 1;
        }
    }
    if (dp[u] == mid){
        cnt++;
        dp[u] = -1e9;
        farcry[u] = 0;
        hp[u] = 0;
    }
    if (u == 1){
        if (dp[u] == 0 && a[u] && farcry[u] > mid) cnt++;
        else if (dp[u] >= 1) cnt++;
    }
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    if (fopen("A.inp", "r")){
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    ll n, m;
    cin >> n >> m;
    ll res = 0;
    for (int i = 1; i <= n; i++){
        cin >> a[i];
        if (a[i] == 1) res++;
    }
    for (int i = 1; i < n; i++){
        ll u, v;
        cin >> u >> v;
        node[u].push_back(v);
        node[v].push_back(u);
    }
    if (res <= m) return cout << 0, 0;
    ll l = 1, h = n;
    while (l <= h){
        mid = (l + h) >> 1;
        cnt = 0;
        memset(hp, 0, sizeof(hp));
        for (int i = 1; i <= n; i++) farcry[i] = 1e9, dp[i] = -1e9;
        dfs(1, 1);
        if (cnt > m) l = mid + 1;
        else h = mid - 1;
    }
    cout << l;
}
/*
*/

Compilation message

dyn.cpp: In function 'int main()':
dyn.cpp:41:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   41 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
dyn.cpp:42:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   42 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 7424 KB Output is correct
2 Correct 5 ms 7424 KB Output is correct
3 Correct 6 ms 8576 KB Output is correct
4 Correct 6 ms 8576 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 8608 KB Output is correct
2 Correct 6 ms 8576 KB Output is correct
3 Correct 6 ms 8576 KB Output is correct

Subtask #3
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 8576 KB Output is correct
2 Correct 7 ms 8576 KB Output is correct

Subtask #4
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 8576 KB Output is correct
2 Correct 7 ms 8576 KB Output is correct

Subtask #5
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 9088 KB Output is correct
2 Correct 40 ms 9636 KB Output is correct
3 Correct 46 ms 9856 KB Output is correct
4 Correct 56 ms 11520 KB Output is correct

Subtask #6
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 74 ms 11008 KB Output is correct
2 Correct 172 ms 11768 KB Output is correct
3 Correct 304 ms 12152 KB Output is correct
4 Correct 265 ms 14968 KB Output is correct

Subtask #7
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 297 ms 13048 KB Output is correct
2 Correct 311 ms 13304 KB Output is correct
3 Correct 397 ms 12920 KB Output is correct
4 Correct 504 ms 18064 KB Output is correct

Subtask #8
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 921 ms 17656 KB Output is correct
2 Correct 1039 ms 19272 KB Output is correct
3 Correct 1602 ms 26872 KB Output is correct
4 Correct 1576 ms 26744 KB Output is correct

Subtask #9
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1883 ms 24188 KB Output is correct
2 Correct 1546 ms 26988 KB Output is correct
3 Correct 1864 ms 31480 KB Output is correct

Subtask #10
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1865 ms 30472 KB Output is correct
2 Correct 1554 ms 26916 KB Output is correct
3 Correct 1997 ms 36984 KB Output is correct
4 Correct 655 ms 27240 KB Output is correct