题目分析：计算距离，然后排序
代码分析：维护三个变量记录最小值，次小值，次次小值，外加三个记录编号的变量。因为这是获取小值，所以三变量初始值应为一个很大的数。
满分C++代码：
#include <iostream> #include <cmath> using namespace std; int main() { int n, c_x, c_y; scanf("%d%d%d", &n, &c_x, &c_y); int x, y; int a = 0x3f3f3f3f, b = 0x3f3f3f3e, c = 0x3f3f3f3d; int a_i = 0, b_i = 0, c_i = 0; for(int i=1; i<=n; i++) { scanf("%d%d", &x, &y); int dis = pow((x - c_x) , 2) + pow((y - c_y) , 2); if(dis < c) { a = b; b = c; c = dis; a_i = b_i; b_i = c_i; c_i = i; } else if(dis < b) { a = b; b = dis; a_i = b_i; b_i = i; } else if(dis < a) { a = dis; a_i = i; } } printf("%d\n%d\n%d", c_i, b_i, a_i); return 0; }