Submission #413061

#	Time	Username	Problem	Language	Result	Execution time	Memory
413061		nxteru	Handcrafted Gift (IOI20_gift)	C++14	100 / 100	194 ms	29104 KiB

gift

#include "gift.h"
using namespace std;
int ims[500005],s[500005];
int construct(int n, int r,vector<int> a,vector<int> b,vector<int> x) {
    vector<pair<int,int>>p[2];
    for(int i=0;i<r;i++){
        p[x[i]-1].push_back(make_pair(a[i],b[i]));
    }
    for(auto i:p[0]){
        ims[i.first]++;
        ims[i.second]--;
    }
    for(int i=1;i<n;i++)ims[i]+=ims[i-1];
    for(int i=1;i<n;i++){
        if(ims[i-1]==0)s[i]=1;
        if(i>0)s[i]+=s[i-1];
    }
    for(auto i:p[1]){
        if(s[i.second]==s[i.first])return 0;
    }
    string ans="R";
    for(int i=0;i<n-1;i++){
        if(ims[i]>0)ans+=ans.back();
        else{
            if(ans.back()=='R')ans+='B';
            else ans+='R';
        }
    }
    craft(ans);
    return 1;
}

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 20 / 20
• Subtask 4: 25 / 25
• Subtask 5: 30 / 30