【leetcode】下一个排列

int cmp(const void* a, const void* b){
    return *(int*)a-*(int*)b;
}
void nextPermutation(int* nums, int numsSize){
    int i,left,pst=0,val,temp;
    int* arr=(int*)calloc(sizeof(int),numsSize);
    for(i=numsSize-1; i>=0; i--){        
        if (i!=numsSize-1 && nums[i]<nums[i+1])
        {
            val=nums[i];
            left=i;
            break;
        }
        arr[pst++]=nums[i];
    }
    if (i==-1)
    {
        qsort(nums,numsSize,sizeof(int),cmp);
        return;
    }
    for (i=0; i<pst && arr[i]<=val; i++);
    nums[left]=arr[i];
    arr[i]=val;
    for (i=left+1; i<numsSize; i++)
        nums[i]=arr[i-(left+1)];
}