花千骨人物手绘:求教各位高手，帮我解解这两道c语言题吧，急需阿

1.
void DeleteDigit(char *dst, char *src)
{
if(NULL == dst) return;
if(NULL == src) return;
while(*src)
{
if(*src >= '0' && *src <= '9')
continue;
*dst++ = *src++;
}
}
2.
void SelectionSort(int *arr, int low, int high)
{
int i, j, k, temp;
int len = high - low + 1;
if(NULL == arr) return;
for(i = 0; i < len - 1; i++)
{
k = i;
for(j = i + 1; j < len; j++)
{
if(arr[j] < a[k]) k = j;
}
if(k != i)
{
temp = arr[i];
arr[i] = arr[k];
arr[k] = temp;
}
}
}

1
#include "string.h"
#include "alloc.h"

void fn_DelNum(char *str)
{
char *pTemp; //临时字符串
int cont,cont2; // 两个计数器
pTemp = malloc(strlen(str)+1); //分配空间
pTemp[strlen(str)] = 0;
for(cont = 0 cont2 = 0; cont < strlen(str); cont++)
{
if(str[cont] > '9' || str[cont]< '0')
{
pTemp[cont2] = str[cont];
cont2++;
}//if
}//for
strcpy(str, pTemp);
free(pTemp);
return;
}