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Submission #580886

# Submission time Handle Problem Language Result Execution time Memory
580886 2022-06-22T05:15:47 Z 조영욱(#8362) Beads and wires (APIO14_beads) C++17
0 / 100
 9 ms 12796 KB 
#include <bits/stdc++.h>
using namespace std;

int n;
typedef pair<int,int> P;
vector<P> adj[200001];
long long dp[200001][2];
vector<P> son[200001];
const long long nn=-2e9-7;

void dfs(int v,int prev) {
    for(int i=0;i<adj[v].size();i++) {
        P nt=adj[v][i];
        if (nt.first!=prev) {
            son[v].push_back(nt);
            dfs(nt.first,v);
        }
    }
}

long long ans(int v,int type) {
    if (dp[v][type]!=-1) {
        return dp[v][type];
    }
    if (type==0) {
        long long mx1=nn;
        long long mx2=nn;
        long long ret=0;
        for(int i=0;i<son[v].size();i++) {
            ret+=max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second);
            if (mx1<son[v][i].second+ans(son[v][i].first,0)-max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second)) {
                mx2=mx1;
                mx1=son[v][i].second+ans(son[v][i].first,0)-max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second);
            }
            else if (mx2<son[v][i].second+ans(son[v][i].first,0)-max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second)) {
                mx2=son[v][i].second+ans(son[v][i].first,0)-max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second);
            }
        }
        if (mx1+mx2>0) {
            ret+=mx1+mx2;
        }
        return dp[v][type]=ret;
    }
    long long mx=nn;
    long long ret=0;
    for(int i=0;i<son[v].size();i++) {
        ret+=max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second);
        if (mx<son[v][i].second+ans(son[v][i].first,0)-max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second)) {
            mx=son[v][i].second;
        }
    }
    return dp[v][type]=ret+mx;
}

int main(void) {
    scanf("%d",&n);
    for(int i=1;i<n;i++) {
        int u,v,w;
        scanf("%d %d %d",&u,&v,&w);
        adj[u].push_back(P(v,w));
        adj[v].push_back(P(u,w));
    }
    memset(dp,-1,sizeof(dp));
    dfs(1,0);
    printf("%lld\n",ans(1,0));
}

Compilation message

beads.cpp: In function 'void dfs(int, int)':
beads.cpp:12:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |     for(int i=0;i<adj[v].size();i++) {
      |                 ~^~~~~~~~~~~~~~
beads.cpp: In function 'long long int ans(int, int)':
beads.cpp:29:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |         for(int i=0;i<son[v].size();i++) {
      |                     ~^~~~~~~~~~~~~~
beads.cpp:46:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |     for(int i=0;i<son[v].size();i++) {
      |                 ~^~~~~~~~~~~~~~
beads.cpp: In function 'int main()':
beads.cpp:56:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |     scanf("%d",&n);
      |     ~~~~~^~~~~~~~~
beads.cpp:59:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |         scanf("%d %d %d",&u,&v,&w);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 12756 KB Output is correct
2 Correct 9 ms 12756 KB Output is correct
3 Correct 8 ms 12700 KB Output is correct
4 Incorrect 6 ms 12796 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #2
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 12756 KB Output is correct
2 Correct 9 ms 12756 KB Output is correct
3 Correct 8 ms 12700 KB Output is correct
4 Incorrect 6 ms 12796 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 12756 KB Output is correct
2 Correct 9 ms 12756 KB Output is correct
3 Correct 8 ms 12700 KB Output is correct
4 Incorrect 6 ms 12796 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 12756 KB Output is correct
2 Correct 9 ms 12756 KB Output is correct
3 Correct 8 ms 12700 KB Output is correct
4 Incorrect 6 ms 12796 KB Output isn't correct
5 Halted 0 ms 0 KB -