Plus One Problem & Solution
Given a non-empty array of decimal digits representing a non-negative integer, increment one to the integer.
See the plus one problem on LeetCode.
C++ Solution
#pragma GCC optimize("Ofast")
#pragma GCC optimization("unroll-loops")
static const int _=[](){std::ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);return 0;}();
class Solution {
public:
vector<int> plusOne(vector<int>& digits) {
int carryover = 1;
for (int i = digits.size() - 1; i >= 0; --i) {
digits[i] += carryover;
carryover = digits[i] / 10;
digits[i] %= 10;
}
if (carryover > 0) {
digits.insert(digits.begin(), carryover);
}
return digits;
}
};