题目链接：https://nanti.jisuanke.com/t/41384
There are nn points in an array with index from 11 to nn, and there are two operations to those points.
1: 1 x1 x marking the point xx is not available
2: 2 x2 x query for the index of the first available point after that point (including xx itself) .
Input
q is the number of queries, z is the type of operations, and x is the index of operations. 1≤x<n<109,1≤x<n<109 q<106and z is 1 or 2.
Output
Output the answer for each query.
样例输入
5 3 1 2 2 2 2 1
样例输出
3 1
因为数字比较多，我们不能开数组并查集，但是询问次数不多，所以询问涉及的数字不多，我们哈希即可。
#pragma GCC optimize(2)
#include<bits/stdc++.h>
//#define int long long
using namespace std;
unordered_map<int,int> mp;
int n,q;
int find(int x){
if(!mp[x]) return x;
if(mp[x]==-1) return -1;
else return mp[x]=find(mp[x]);
}
signed main(){
scanf("%d %d",&n,&q); mp[n]=-1;
while(q--){
int z,x; scanf("%d %d",&z,&x);
if(z==1) mp[x]=find(x+1);
else printf("%d
",find(x));
}
return 0;
}