全排列

全排列在面试中经常会出到。用递归很容易解决。看了下面的例子大家一下就懂了。

#include<stdio.h>

void swap(int *arrRange, int location1, int location2)
{
    int temp = arrRange[location1];
    arrRange[location1] = arrRange[location2];
    arrRange[location2] = temp;
}

void printArrRange(int *arrRange, int length)
{
    int i;
    for(i = 0; i < length; i++)
    {
        printf("%d",arrRange[i]);
    }
    printf("\n");
}

void allRange(int *arrRange, int begin, int end)
{
    if(begin == end)
    {
        printArrRange(arrRange, end);
    }

    int i;
    for(i = begin; i < end; i++)
    {
        swap(arrRange, begin, i);
        allRange(arrRange, begin + 1, end);
        swap(arrRange, begin, i);
    }
}

int main()
{
    int arrRange[4] = {1,2,3,4};
    allRange(arrRange, 0, 4);
    return 0;
}