经典的排列算法
public class Solution {
public void nextPermutation(int[] nums) {
if(nums.length==1)
{
return;
}
int a=nums.length-2;
while(a>=0&&nums[a+1]<=nums[a])
{
a--;
}
if(a==-1)
{
reverse(nums,0,nums.length-1);
return;
}
int b=nums.length-1;
while(nums[b]<=nums[a])
{
b--;
}
int temp=nums[b];
nums[b]=nums[a];
nums[a]=temp;
reverse(nums,a+1,nums.length-1);
}
public void reverse(int []nums,int start,int end)
{
for(int i=start,j=end;i<j;i++,j--)
{
int temp=nums[i];
nums[i]=nums[j];
nums[j]=temp;
}
}
}