hdu 4585 shaolin—— STL lower_bound的应用

#include<iostream>
#include<cstdio>
#include<string>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<iomanip>
#include<stdlib.h>
#include<set>
#include<map>
#include<queue>
using namespace std;

int main()
{
    int n,i;
    while(scanf("%d",&n)&&n!=0)
    {

        int resulta[100005],resultb[100005];
        map<int,int> m;
        map<int,int> ::iterator it;
        m[1000000000]=1;
        for(i=0; i<n; i++)
        {

            int id;
            int grade;
            scanf("%d%d",&id,&grade);
            resulta[i]=id;
            it=m.lower_bound(grade);
            if(it==m.end())
            {
                it--;
                resultb[i]=it->second;
            }
            else if(it==m.begin())
            {
                resultb[i]=it->second;
            }
            else
            {
                int Maxgrade=it->first;
                int Maxid=it->second;
                it--;
                int Mingrade=it->first;
                int Minid=it->second;
                if(grade-Mingrade<=Maxgrade-grade)
                {
                    resultb[i]=Minid;

                }
                else resultb[i]=Maxid;
            }

            m[grade]=id;
        }
        for(i=0; i<n; i++)
        {
            printf("%d %d\n",resulta[i],resultb[i]);
        }

    }
    return 0;
}