Next bigger number with the same digits

• Time : $O(log(n))$
• Space : $O(log(n))$

#include <bits/stdc++.h>
using namespace std;
vector<int> build(long n) {
    vector<int> res;
    while(n) {
        res.push_back(n % 10);
        n /= 10;
    }
    reverse(begin(res), end(res));
    return res;
}
long nextBigger(long n) {
    vector<int> perm = build(n);
    next_permutation(begin(perm), end(perm));
    long res = 0;
    for(int i = 0; i < perm.size(); i++) res = res * 10 + perm[i];
    return res > n ? res : -1;
}