51nod 1100:斜率最大

题目链接

斜率最大点对横坐标必相邻

#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e4 + 100;struct point
{int x, y, pos;bool operator < (const point& rhs)const{return x<rhs.x;}
} a[maxn];
double xielv(point a, point b)
{return (a.y-b.y)*1.0/(a.x-b.x);
}int main()
{int n, x, y;scanf("%d", &n);for(int i=0; i<n; i++){scanf("%d%d", &x, &y);a[i] = (point){x, y, i+1};}sort(a, a+n);double maxxl = -1e9;int index = -1;for(int i=1; i<n; i++){if(maxxl < xielv(a[i], a[i-1])){maxxl = xielv(a[i], a[i-1]);index = i;}}if(a[index].x < a[index-1].x) printf("%d %d\n", a[index].pos, a[index-1].pos);else printf("%d %d\n", a[index-1].pos, a[index].pos);
}