Question

二维数组顺时针,逆时针排序问题一个二维数组,传入x,y分别代表行数和列数,比如x = 4 y = 4;如果打印出来是 0

Answer 1

// 求面积.cpp :定义控制台应用程序的入口点.

#include "stdafx.h"

#include

#include

//

double square(float num1[5],float num2[5])

{

double side[7],length[3],squ[3];

int i;

for(i=0;i<4;i++) /*两点之间的线段长*/

side[i]=sqrt((num1[i+1]-num1[i])*(num1[i+1]-num1[i])+(num2[i+1]-num2[i])*(num2[i+1]-num2[i]));

side[5]=sqrt((num1[2]-num1[0])*(num1[2]-num1[0])+(num2[2]-num2[0])*(num2[2]-num2[0]));

side[6]=sqrt((num1[4]-num1[2])*(num1[4]-num1[2])+(num2[4]-num2[2])*(num2[4]-num2[2]));

side[4]=sqrt((num1[4]-num1[0])*(num1[4]-num1[0])+(num2[4]-num2[0])*(num2[4]-num2[0]));

length[0]=(side[0]+side[1]+side[5])*1.0/2;

squ[0]=sqrt(length[0]*(length[0]-side[0])*(length[0]-side[1])*(length[0]-side[5])); /*求三角形的面积*/

length[1]=(side[2]+side[3]+side[6])*1.0/2;

squ[1]=sqrt(length[1]*(length[1]-side[2])*(length[1]-side[3])*(length[1]-side[6]));

length[2]=(side[4]+side[5]+side[6])*1.0/2;

squ[2]=sqrt(length[2]*(length[2]-side[4])*(length[2]-side[5])*(length[2]-side[6]));

return (squ[0]+squ[1]+squ[2]); /*返回三角形的面积之和*/

}

int _tmain(int argc,_TCHAR* argv[])

{

float num1[5]=,num2[5]=;

double square1=0,squ[3]=;

int i;

printf("please input the points in turnn");

for(i=0;i<5;i++)

{

scanf("%f%f",&num1[i],&num2[i]);

printf("%f%fn",num1[i],num2[i]);

}

square1=square(num1,num2); /*五边形面积等于三个三角形面积之和*/

printf("%f",square1);

return 0;

}