51nod 1100 斜率最大

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;
}