QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#778172 | #2596. Even Forest | niumachaoren | TL | 9ms | 61960kb | C++14 | 1.3kb | 2024-11-24 13:05:38 | 2024-11-24 13:05:38 |
Judging History
answer
#include<bits/stdc++.h>
inline void read(int &x){
x=0;char ch=getchar();
while(!isdigit(ch))ch=getchar();
while(isdigit(ch)){
x=(x<<1)+(x<<3)+(ch^48);
ch=getchar();
}
}
using namespace std;
const int maxn=1e6+10;
int n,dp[maxn][2],g[maxn][2],rt;
vector<int>e[maxn<<1];
void dfs(int u,int fa){
if(e[u].size()==1&&u!=rt){
// cout<<rt<<'\n';
dp[u][0]=0;
return ;
}
int siz=0;
for(int v:e[u]){
if(v==fa)continue;
siz++;
dfs(v,u);
}
for(int i=0;i<=siz;i++){
g[i][0]=g[i][1]=0x3f3f3f3f;
}
g[0][0]=g[0][1]=0;
for(int i=1;i<=e[u].size();i++){
int v=e[u][i-1];
if(v==fa)continue;
for(int j=i;j>=0;j--){
g[j][0]=min(g[j][0]+dp[v][1],g[j-1][0]+dp[v][0]);//选j个偶的留下
g[j][1]=min(g[j][1]+dp[v][0],g[j-1][1]+dp[v][1]);//选j个奇的留下
}
}
for(int j=0;j<=siz;j++){
dp[u][0]=min(dp[u][0],g[j][1]+siz-j);
dp[u][1]=min(dp[u][1],g[j][0]+siz-j);
}
}
int main(){
read(n);
for(int i=1;i<n;i++){
int u,v;
read(u),read(v);
e[u].push_back(v);
e[v].push_back(u);
}
int cnt=0,cnt2=0;
for(int i=1;i<=n;i++){
if(e[i].size()==1)cnt++;
}
if(cnt==2){
cout<<((n&1)^1)<<'\n';
return 0;
}
int ans=0;
memset(dp,0x3f,sizeof(dp));
rt=1;
dfs(rt,0);
ans=min(dp[rt][1],dp[rt][0]);
cout<<ans<<'\n';
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 9ms
memory: 51560kb
input:
4 1 2 2 3 3 4
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 0ms
memory: 61960kb
input:
4 1 2 1 3 1 4
output:
0
result:
ok 1 number(s): "0"
Test #3:
score: 0
Accepted
time: 8ms
memory: 59964kb
input:
6 1 2 2 3 4 2 4 5 6 4
output:
1
result:
ok 1 number(s): "1"
Test #4:
score: 0
Accepted
time: 4ms
memory: 59928kb
input:
1
output:
0
result:
ok 1 number(s): "0"
Test #5:
score: 0
Accepted
time: 4ms
memory: 51180kb
input:
2 1 2
output:
1
result:
ok 1 number(s): "1"
Test #6:
score: 0
Accepted
time: 7ms
memory: 51976kb
input:
3 2 3 3 1
output:
0
result:
ok 1 number(s): "0"
Test #7:
score: 0
Accepted
time: 8ms
memory: 59872kb
input:
4 2 3 3 1 3 4
output:
0
result:
ok 1 number(s): "0"
Test #8:
score: 0
Accepted
time: 4ms
memory: 50596kb
input:
5 4 2 2 3 4 1 5 3
output:
0
result:
ok 1 number(s): "0"
Test #9:
score: 0
Accepted
time: 8ms
memory: 59940kb
input:
6 4 3 1 4 2 4 5 2 4 6
output:
1
result:
ok 1 number(s): "1"
Test #10:
score: 0
Accepted
time: 4ms
memory: 60036kb
input:
50 21 22 22 27 22 7 22 12 22 13 43 22 36 22 35 22 6 22 10 22 22 38 19 22 34 22 8 22 22 44 22 3 9 22 22 16 23 22 18 22 22 25 22 5 22 2 22 15 46 22 37 22 48 22 33 22 22 17 31 22 22 29 22 28 22 49 4 22 22 26 41 22 22 32 22 50 22 20 22 30 24 22 40 22 22 45 14 22 22 11 42 22 39 22 1 22 47 22
output:
0
result:
ok 1 number(s): "0"
Test #11:
score: -100
Time Limit Exceeded
input:
1000000 851841 325834 455962 325834 135775 325834 525341 325834 265267 325834 868520 325834 834325 325834 867971 325834 325834 879726 325834 242607 325834 106951 122113 325834 325834 499633 727580 325834 325834 200171 325834 178877 325834 493841 957118 325834 325834 809324 325834 641895 325834 33338...