图的遍历 深度优先搜索 and 广度优先搜索

深度优先搜索

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#define inf 0x3f3f3f3f
using namespace std;

const int maxn = 100;
int vis[101],sum,n,e[101][101];

void dfs(int cur){
    int i;
    printf("%d ",cur);
    sum++;
    if(sum==n)return ;
    for(i=1;i<=n;i++){
        if(e[cur][i]==1&&vis[i]==0){
            vis[i]=1;
            dfs(i);
        }
    }
    return ;
}

int main(){
    int i,j,m,a,b;
    scanf("%d%d",&n,&m);
    memset(vis,0,sizeof(vis));
    for(i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            if(i==j)e[i][j]=0;
            else e[i][j]=inf;
        }
    }
    for(int i=1;i<=m;i++){
        scanf("%d%d",&a,&b);
        e[a][b]=1;
        e[b][a]=1;
    }
    vis[1]=1;
    dfs(1);
    return 0;
}

广度优先搜索

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#define inf 0x3f3f3f3f
using namespace std;

const int maxn = 100;

int main(){
    int i,j,m,n,a,b,cur,vis[101]={0},e[101][101];
    int que[10001],head,tail;
    scanf("%d%d",&n,&m);
    for(i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            if(i==j)e[i][j]=0;
            else e[i][j]=inf;
        }
    }
    for(i=1;i<=m;i++){
        scanf("%d%d",&a,&b);
        e[a][b]=1;
        e[b][a]=1;
    }
    head=1;
    tail=1;
    que[tail]=1;
    tail++;
    vis[1]=1;
    while(head<tail&&tail<=n){
        cur=que[head];
        for(i=1;i<=n;i++){
            if(e[cur][i]==1&&vis[i]==0){
                que[tail]=i;
                tail++;
                vis[i]=1;
            }
            if(tail>n)break;
        }head++;
    }
    for(i=1;i<tail;i++){
        printf("%d ",que[i]);
    }
}