題目連結: https://zerojudge.tw/ShowProblem?problemid=d809
# 解題思路
窮舉所有的三角形面積吧！！
(鞋帶公式好好用！！)
# 程式碼
#include<stdio.h> | |
#include<stdlib.h> | |
struct D{ | |
int x, y; | |
}s[200]; | |
main() { | |
int N, a, b, c; | |
while(scanf("%d", &N) == 1) { | |
for(a = 0; a < N; a++) | |
scanf("%d %d", &s[a].x, &s[a].y); | |
int max = 0, t; | |
for(a = 0; a < N; a++) | |
for(b = a+1; b < N; b++) | |
for(c = b+1; c < N; c++) { | |
t = abs(s[a].x*s[b].y + s[b].x*s[c].y + s[c].x*s[a].y | |
-s[a].y*s[b].x - s[b].y*s[c].x - s[c].y*s[a].x | |
); | |
if(t > max) max = t; | |
} | |
printf("%.2lf\n", max / 2.0); | |
} | |
return 0; | |
} |
