假期集训Day 4

图论

基本实现

#include <cstdio>
struct node{
    int to,next,val;
}edge[N];
void add(int x,int y,int val1){
    e[cnt]=(node){y,head[x],val1};
    head[x]=cnt++;
}
memset(head,-1,sizeof(head));
cnt=0;
for(int i=head[x];i!=-1;i=edge[i].next){
    int to1=edge[i].to;
    //do something
}

My code

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#define N 5005
#define M 20005
using namespace std;
int cnt=0,head[N]; 
struct node{
    int to,next,val;
}edge[N];
void add(int x,int y,int val1){
    edge[++cnt].next=head[x];
    edge[cnt].to=y;
    edge[cnt].val=val1;
    head[x]=cnt;
    
}
int main(){
    
}
memset(head,-1,sizeof(head));
for(int i=head[x];i!=-1;i=edge[i].next){
    int to1=edge[i].to;
    //do something
}