42（map）

#include <iostream>
#include <map>
#include <cstdio>
#include <cmath>
using namespace std;

//key:实力值power  value:id号 
int main(){
    map<int,int> members;
    members[1000000000] = 1;
    int n,id,power;
    scanf("%d",&n);
    map<int,int>::iterator it,pre,next;
    while(n --){
        scanf("%d%d",&id,&power);
        members[power] = id;
        it = pre = next = members.find(power);
        pre --; next ++;
        if(it == members.begin())
          printf("%d %d\n",id,next -> second);
        else if(next == members.end())
          printf("%d %d\n",id,pre -> second);
        else if(abs(it -> first - pre -> first) > abs(it -> first - next -> first))
          printf("%d %d\n",id,next -> second);
        else
          printf("%d %d\n",id,pre -> second);
    }
    return 0;
}