C语言编程实例

//1.快速排序算法

#include <stdio.h>

#define SIZE 10

void fastSort(int *a, int iLeft,int iRight)

{

int i = 0;

int j = 0;

int k = 0;

i = iLeft;

j = iRight;

k = a[iLeft];

if(i >= j)

{

return;

}

while(i < j)

{

while(i < j && k <= a[j])

{

--j;

}

a[i] = a[j];

while(i < j && k >= a[i])

{

++i;

}

a[j] = a[i];

}

a[i] = k;

fastSort(a,iLeft,i-1);

fastSort(a,i+1,iRight);

}

int main()

{

int i = 0;

int a[SIZE] = {6,2,3,7,8,9,4,11,5,12};

fastSort(a,0,9);

for(i=0;i<10;++i)

printf("%5d",a[i]);

printf("\n");

return 0;

}

//2.判断一个整数是否为对称数,如12321

#include<stdio.h>

int main()

{

int num =12321;

int sum = 0;

int temp = 0;

int n = num;

while(n > 0)

{

temp = n % 10;

sum = sum * 10 + temp;

n /= 10;

}

if(sum == num)

printf("是对称整数.\n");

else

printf("不是对称整数.\n");

return 0;

}

//3.判断一个数是否为对称数如1234.321不准用字条处理

#include <stdio.h>

#include <stdlib.h>

#define SIZE 100

int isSymmetryNum(double num)

{

int flag = 0;

char *cp;

char cpNum[SIZE] = {0};

char caNum[SIZE] = {0};

int i = 0;

int iLen = 0;

int count = 8;

int j = 0;

cp = gcvt(num,count,cpNum);

//for(i=0;i<8;++i)

//printf("%c",cp[i]);

//printf("\n");

//for(i=0;i<8;++i)

//printf("%c",cpNum[i]);

//printf("\n");

iLen = strlen(cp);

//printf("iLen = %d\n",iLen);

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

{

if(cp[i]!=46)

{

caNum[j]=cp[i];

j++;

}

}

j--;

for(i=0;i= j/2;++i)

{

if(caNum[i] != caNum[j-i])

{

flag = 0;

return flag;

}

}

flag = 1;

//puts(cp);

return flag;

}

int main()

{

double num = 1234.321;

int i = 0;

i = isSymmetryNum(num);

if(1 == i)

printf("it is a symmetry num.\n");

else

printf("it is not a symmetry num.\n");

return 0;

}