[Leetcode 52] Next Permutation report

Question:

Given a list of integers, which denote a permutation.

Find the next permutation in ascending order.

Example

[1,3,2,3]for, the next permutation is[1,3,3,2]

[4,3,2,1]for, the next permutation is[1,2,3,4]

Note

The list may contains duplicate integers.

What is Next permutation?

The permutation with current charactors, which is lexicographically next.

1234-1243
4321-1234
1243-1324
2134-2143

Idea:

Answer:

 classSolution {  Public:     /** * @param nums:an array of integers * @return: An array of integers that ' s next permuation      */vector<int> Nextpermutation (vector<int> &nums) {         //Write your code here         if(Nums.size () <=1) {             returnnums;         }                  //Find first element is smaller that next element         intFirst_small_index =-1;          for(inti = nums.size ()-2; I >=0; --i) {             if(Nums[i] < nums[i+1]) {First_small_index =i;                  Break;             }         }         //find the first element is just bigger than the element we found         if(First_small_index! =-1) {             intFirst_bigger_index =First_small_index;              for(inti = First_small_index +1; I < nums.size (); ++i) {                 if(Nums[i] >Nums[first_small_index]) {First_bigger_index =i;}Else {                      Break;                 }             } swap (Nums[first_small_index], Nums[first_bigger_index]);         }         //Reverse Rest ArrayReverse (Nums.begin () + First_small_index +1, Nums.end ());                  returnnums;     }};

[Leetcode 52] Next Permutation report