POJ 3140 contents division "suggestions collection"

Hello everyone , I meet you again , I'm the king of the whole stack .

The main idea of the topic ：

Give me a tree . Find the minimum value of the sum of the node weights of the two subtrees after removing an edge .

Their thinking ：

I don't know how to use tree DP do , It's just a DFS It's over . I hit back once .

Think about the code in detail .

Here's the code ：

#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <iostream>
#include <math.h>
#include <stdlib.h>
#include <vector>
#include <string>
#include <map>
#include <queue>
using namespace std;

int min(int a,int b)
{
    if(a>b)a=b;
    return a;
}
int max(int a,int b)
{
    if(a<b)a=b;
    return a;
}
struct node
{
    int to,next;
} edge[100005*2];
int n,m,cnt,head[100005];
long long weight[100005],min1,sum;
const long long inf = 100000000000000ll;
bool vis[100005];
void addedge(int u,int v)
{
    edge[cnt].to=v;
    edge[cnt].next=head[u];
    head[u]=cnt++;
    edge[cnt].to=u;
    edge[cnt].next=head[v];
    head[v]=cnt++;
}
bool chack(int src)
{
    int t=head[src];
    while(t!=-1)
    {
        if(!vis[edge[t].to])return true;
        t=edge[t].next;
    }
    return false;
}
long long llaabs(long long num)
{
    if(num<0)num=-num;
    return num;
}
long long dfs(int src)
{
    long long ans=weight[src],temp;
    vis[src]=true;
    if(chack(src))
    {
        int t=head[src];
        while(t!=-1)
        {
            if(!vis[edge[t].to])
            {
                temp=dfs(edge[t].to);
                min1=min(min1,llaabs(sum-temp-temp));
                ans+=temp;
            }
            t=edge[t].next;
        }
    }
    return ans;
}
int main()
{
    int case1=1;
    while(scanf("%d%d",&n,&m),n||m)
    {
        cnt=0;
        int u,v;
        min1=inf;
        sum=0;
        memset(vis,false,sizeof(vis));
        memset(head,-1,sizeof(head));
        for(int i=1; i<=n; i++)
        {
            scanf("%lld",&weight[i]);
            sum+=weight[i];
        }
        for(int i=0; i<m; i++)
        {
            scanf("%d%d",&u,&v);
            addedge(u,v);
        }
        dfs(1);
        printf("Case %d: %lld\n",case1++,min1);
    }
    return 0;
}

Copy

Publisher ： Full stack programmer stack length , Reprint please indicate the source ：https://javaforall.cn/116301.html Link to the original text ：https://javaforall.cn