leetcode_permutaion

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
    int a[3] = { 1,3,2};
    vector<int>num(a, a + 3);
    auto rfirst = num.rbegin();
    auto rend = num.rend();
    auto p = next(rfirst);
    while (p != rend && *p > *(prev(p)))
        ++p;
    if (p == rend)
        reverse(num.begin(), num.end());
    else
    {
        for (auto i = rfirst; i!=rend; ++i)
        {
            if (*i > *p)swap(*i, *p);
            reverse(rfirst, i);
        }
    }
    for (auto i : num)
    {
        cout << i << " ";
    }
    system("pause");
    return 0;
}