Codeforces Round #652 (Div. 2) E. DeadLee 构造

#include<map>
#include<queue>
#include<time.h>
#include<limits.h>
#include<cmath>
#include<ostream>
#include<iterator>
#include<set>
#include<stack>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define rep_1(i,m,n) for(int i=m;i<=n;i++)
#define mem(st) memset(st,0,sizeof st)
int read()
{
    int res=0,ch,flag=0;
    if((ch=getchar())=='-')             //判断正负
        flag=1;
    else if(ch>='0'&&ch<='9')           //得到完整的数
        res=ch-'0';
    while((ch=getchar())>='0'&&ch<='9')
        res=res*10+ch-'0';
    return flag?-res:res;
}
typedef long long ll;
typedef pair<int,int> pii;
typedef unsigned long long ull;
typedef pair<double,double> pdd;
const int inf = 0x3f3f3f3f;
const int N=2e5+10;
int w[N];
vector<int>ans;
vector<pii>e[N];
queue<int>q;
bool vis[N],in_ans[N];
void solve()
{
    memset(vis,0,sizeof vis);
    memset(in_ans,0,sizeof in_ans);
    int n,m;
    cin>>n>>m;
    for(int i=1;i<=n;i++)
        cin>>w[i];
    for(int i=1;i<=m;i++)
    {
        int x,y;
        cin>>x>>y;
        e[x].push_back({y,i});
        w[x]--;
        e[y].push_back({x,i});
        w[y]--;
    }
    //这些是再怎么吃，都不会吃完的，那么就可以把这些人，安排到最后
    //那另外一种食物吐出来 
    for(int i=1;i<=n;i++)
        if(w[i]>=0)
            q.push(i),vis[i]=1;
    while(q.size())
    {
        int food=q.front();
        q.pop();
        for(auto p:e[food])
        {
            if(!in_ans[p.second])
                ans.push_back(p.second),in_ans[p.second]=1;
            if(!vis[p.first])
            {
                w[p.first]++;//把另外一种吐出来 
                if(w[p.first]>=0)
                {
                    vis[p.first]=1;
                    q.push(p.first);
                }
            }
        }
    }
    //倒着输出 
    if((int)ans.size()==m)
    {
        cout<<"ALIVE"<<endl;
        for(int i=ans.size()-1;i>=0;i--)
            cout<<ans[i]<<" ";
        cout<<endl;
    }
    else
        cout<<"DEAD"<<endl;
}
int main()
{
    int t=1;
    while(t--)
        solve();
    return 0;
}