面试中经常碰到的C语言算法

这段时间有点困惑，在底层待了一段时间，太没有自由和个性了，重新找一下上层C语言无拘无束的感觉

#include <stdio.h>
#include <string.h>

void bubble_sort(int a[], int n)
{
/*冒泡排序*/
    int i, j, t;
    int flag = 1;

    for (i = 0; i < n && flag; i ) {
        flag = 0;
        for (j = 0; j < n - i - 1; j ) {
            if (a[j] < a[j 1]) {
                t = a[j];
                a[j] = a[j 1];
                a[j 1] = t;
                flag = 1;
            }
        }
    }
}

void select_sort(int a[], int n)
{
/*选择排序*/
    int i, j, k, t;

    for (i = 0; i < n - 1; i ) {
        k = i;
        for (j = i 1; j < n; j ) {
            if (a[k] < a[j])
                k = j;
        }
        if (k != i) {
            t = a[i];
            a[i] = a[k];
            a[k] = t;
        }
    }
}

void insert_sort(int a[], int n)
{
/*插入排序*/
    int i, j, t;

    for (i = 1; i < n; i ) {
        t = a[i];
        j = i - 1;
        while (j >= 0 && t > a[j]) {
            a[j 1] = a[j];
            j--;
        }
        a[j 1] = t;
    }
}

int half_find(int a[], int n, int data)
{
/*二分查找*/
    int mid, top = n - 1, bot = 0;
    mid = (top bot) / 2;

    while (top >= bot) {
        if (a[mid] < data)
            bot = mid 1;
        else if (a[mid] > data)
            top = mid - 1;
        else
            return mid;

        mid = (top bot) / 2;
    }
}

void func()
{
    printf("int= %d \n",sizeof(int));
    printf("float= %d \n",sizeof(float));
    printf("double= %d \n",sizeof(double));
}

/*
 * 下面这种写法是有错的
GetMemory(char * p,int num)
{
   p=(char *)malloc(sizeof(char)*num);
}
 */

char * GetMemory(int num)
{
   return (char *)malloc(sizeof(char)*num);
}

void func1()
{
    char *str =NULL;
    char *str1 =NULL;
    char *a="Hello";
    str=GetMemory(100);
    /*str=GetMemory1(&str1,100);*/

    strcpy(str,a);
    printf("%s \n",str);
    strcpy(str,"hello");
    printf("%s \n",str);

/* strcpy(str1,a);*/
    /*printf("%s \n",str1);*/
}

void func2(int a)
{
    int n;
    while(a>0)
    {
        if(a&0x01)
        {
             n;
            a=a>>1;
        }
    }

    printf("n=%d \n",n);
}

int main(void)
{
    int a[5] = {1, 2, 3, 4, 5};
    int i;

    printf("%d\n", half_find(a, 5, 5));
    func();
        func1();
        func2(0x0fffff);
/*    select_sort(a, 5);
    for (i = 0; i < 5; i )
        printf("%d ", a[i]);
        */
    printf("\n");

    return 0;
}