leetcode_problem

  int maxFixedPoints(vector<int>& nums) {
        int n=nums.size();
        vector<pair<int,int>>v;
        for(int i=0;i<n;i++){
            if(i>=nums[i]){
                v.push_back({nums[i],i-nums[i]});
            }
        }
        sort(v.begin(),v.end(),[](const pair<int,int>&a,const pair<int,int>&b){
            if(a.first!=b.first)return a.first<b.first;
            return a.second>b.second;
        });
        vector<int>dp;
        for(auto&[f,s]:v){
            auto it=upper_bound(dp.begin(),dp.end(),s);
            if(it==dp.end())dp.push_back(s);
            else *it=s;
        }
        return dp.size();
    }

for "https://leetcode.com/problems/maximize-fixed-points-after-deletions/"