Add to Array-Form of Integer Problem & Solution
The array-form of an integer num is an array representing its digits in left to right order.
For example, for num = 1321, the array form is [1,3,2,1].
Given num, the array-form of an integer, and an integer k, return the array-form of the integer num + k.
See the add to array-form of integer problem on LeetCode.
C++ Solution
#pragma GCC optimize("Ofast")
#pragma GCC optimization("fast-math")
#pragma GCC optimization("unroll-loops")
#pragma GCC target("avx,avx2,fma")
static const int _=[](){std::ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);return 0;}();
class Solution {
public:
vector<int> addToArrayForm(vector<int>& num, int k) {
int carry = 0;
int i = 0;
while (k > 0 || carry > 0) {
if (i == num.size()) {
num.insert(num.begin(), 0);
}
int j = num.size() - i - 1;
int digit = k % 10;
int sum = num[j] + digit + carry;
k /= 10;
num[j] = sum % 10;
carry = sum / 10;
++i;
}
return num;
}
};