寻找三角形

import math

class Point(object):
    '''定义三个点'''

    def __init__(self, c, x, y, z):
        self.c = c
        self.x = x
        self.y = y
        self.z = z


def valid(l1, l2, l3):
    token = [l1, l2, l3]
    token.sort()
    '''判断三个点是否能构成三角形(两边之和大于第三边)'''
    return token[0] + token[1] > token[2]


def cal_len(p1, p2):
    '''求两点之间的距离'''
    l = pow(p1.x - p2.x, 2) + pow(p1.y - p2.y, 2) + pow(p1.z - p2.z, 2)
    return math.sqrt(l)


def cal_s(c1, c2, c3):
    '''求空间中三个点组成的三角形的面积'''
    l1 = cal_len(c1, c2)
    l2 = cal_len(c2, c3)
    l3 = cal_len(c3, c1)
    ans = 0
    if valid(l1, l2, l3):
        p = (l1 + l2 + l3) / 2
        token = math.sqrt(p * (p - l1) * (p - l2) * (p - l3))
        ans = max(token, ans)
    return ans

def solution(N,nums):
    '''计算三角形的最大面积'''
    ans=0
    for i in range(N):
        for j in range(i + 1, N):
            for k in range(j + 1, N):
                if (nums[i].c == nums[j].c == nums[k].c or len(set([nums[i].c, nums[j].c, nums[k].c])) == 3):
                    '''判断空间中的三个点颜色是否都相同或都不相同'''
                    ans = max(ans, cal_s(nums[i], nums[j], nums[k]))
    return ans

'''主程序'''
N = int(input())
nums = []
for i in range(N):
    c, x, y, z = input().strip().split()
    nums.append(Point(c, int(x), int(y), int(z)))
ans=solution(N,nums)
print('{:.5f}'.format(ans))

while True:
    try:
        n=input()
        n=int(n)
        list1=[]
        for i in range(n):
            list1.append(list(input().split(' ')))
        #print(list1)
        list2=[]
        def iscolor(x,y,z):#判断颜色
            if x!=y and y!=z and x!=z:
                return True
            elif x==y and x==z:
                return True
            else:
                return False
        def distance(x,y):#计算两点距离
            sum1=0
            #print(x[1])
            #print((int(x[1])-int(y[1]))**2)
            sum1=((int(x[1])-int(y[1]))**2+(int(x[3])-int(y[3]))**2+(int(x[2])-int(y[2]))**2)**(0.5)
            return sum1
        def issan(x,y,z):#判断是不是三角形
            if x<(y+z) and z<(x+y) and y<(x+z):
                return True
            else:
                return False
        for x in range(n):
            for y in range(x+1,n):
                for z in range(y+1,n):
                    x_num=list1[x]
                    y_num=list1[y]
                    z_num=list1[z]
                    if iscolor(x_num[0],y_num[0],z_num[0]):
                        #print('ok')
                        l_xy=distance(x_num,y_num)
                        #print(l_xy)
                        l_xz=distance(x_num,z_num)
                        #print(l_xz)
                        l_yz=distance(y_num,z_num)
                        #print(l_yz)
                        if issan(l_xy,l_xz,l_yz):
                            #print('ok')
                            win=(l_xy+l_xz+l_yz)/2
                            square=(win*(win-l_xy)*(win-l_xz)*(win-l_yz))**(0.5)#计算面积
                            list2.append(square)
        #print(list2)
        max_num=max(list2)
        #print(max_num)
        #float('%.2f' % max_num)
        print('{:.5f}'.format(max_num))
        #print(float('%.6f' % max_num))
    except:
        break

参考大佬的算法写的Python代码

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import math
n=int(raw_input())
i=0
ind=[]
while i<n:
    ind.append([a for a in raw_input().split()])
    i+=1
RED=[]
GREEN=[]
BLUE=[]
square=[]
for i in ind:
    if i[0]=='R':
        RED.append([int(o) for o in i[1:]])
    elif i[0]=='G':
        GREEN.append([int(o) for o in i[1:]])
    else:
        BLUE.append([int(o) for o in i[1:]])
def calSquare(l1,l2,l3):
    half = (l1 + l2 + l3) / 2.0
    return math.sqrt(half * (half - l1) * (half - l2) * (half - l3))

for item in [RED,GREEN,BLUE]:
    if len(item)>2:
        for i in range(len(item)-2):
            # item[i]
            for j in range(i+1,len(item)-1):
                # item[j]
                pq = [item[i][z]-item[j][z] for z in range(3)]
                l1 = math.sqrt(sum([pq[z]*pq[z] for z in range(3)]))
                for k in range(i+2,len(item)):
                    # item[k]
                    pr = [item[i][z]-item[k][z] for z in range(3)]
                    qr = [item[j][z] - item[k][z] for z in range(3)]
                    l2 = math.sqrt(sum([pr[z]*pr[z] for z in range(3)]))
                    l3 = math.sqrt(sum([qr[z]*qr[z] for z in range(3)]))
                    if l1 + l2 != l3 or l2 + l3 != l1 or l1 + l3 != l2:
                        s = calSquare(l1, l2, l3)
                        square.append(s)

if len(RED)>2 and len(GREEN)>2 and len(BLUE)>2:
    for p in RED:
        for q in GREEN:
            pq = [p[i] - q[i] for i in range(3)]
            l1 = math.sqrt(sum([pq[z] * pq[z] for z in range(3)]))
            for r in BLUE:
                pr = [p[i] - r[i] for i in range(3)]
                qr = [q[z] - r[z] for z in range(3)]
                l2 = math.sqrt(sum([pr[z] * pr[z] for z in range(3)]))
                l3 = math.sqrt(sum([qr[z] * qr[z] for z in range(3)]))
                if l1+l2!=l3 or l2+l3!=l1 or l1+l3!=l2:
                    s=calSquare(l1,l2,l3)
                    square.append(s)

print min(square)