可以用三个点简单证明斜率最大的直线两个点！
#include <bits/stdc++.h>
#define MAXN 10010
using namespace std;
struct Node{
int x, y, number;
}gg[MAXN];
bool cmp(Node a, Node b){
return a.x<b.x;
}
int main(void){
std::ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
int n;
cin >> n;
for(int i=0; i<n; i++){
cin >> gg[i].x >> gg[i].y;
gg[i].number=i+1;
}
sort(gg, gg+n, cmp);
queue<int> node1, node2;
double cnt=0, cc=0;
for(int i=1; i<n; i++){
cnt=(gg[i].y-gg[i-1].y)*1.0/(gg[i].x-gg[i-1].x);
if(cnt>cc){
cc=cnt;
while(!node1.empty()){
node1.pop();
}
while(!node2.empty()){
node2.pop();
}
node1.push(gg[i-1].number);
node2.push(gg[i].number);
}else if(cnt==cc){
node1.push(gg[i-1].number);
node2.push(gg[i].number);
}
}
while(!node1.empty()){
cout << node1.front() << " " << node2.front() << endl;
node1.pop();
node2.pop();
}
return 0;
}