Leetcode Problem:
Summary
- This problem involves converting a string into an integer by replacing each letter with its position in the alphabet, then transforming the integer by summing its digits repeatedly k times.
Approach
- The approach used is to first convert the string into an integer by subtracting the ASCII value of 'a' from each character and adding 1
- Then, the integer is transformed by summing its digits using a helper function
- This process is repeated k times.
Complexity
- O(n*k) where n is the length of the string and k is the number of transformations.
Explain
- The solution code defines a class Solution with two methods: getSum and getLucky
- The getSum method takes a string as input and returns the sum of its digits
- The getLucky method takes a string and an integer as input and returns the resulting integer after performing the transformations
- The getLucky method first converts the string into an integer, then repeatedly transforms the integer by summing its digits using the getSum method
- The process is repeated k times, and the final result is returned.
Solution Code:
class Solution {
public:
int getSum(string s){
int sum = 0;
for(int i = 0 ; i < s.size(); i++){
sum += s[i] - '0';
}
return sum;
}
int getLucky(string s, int k) {
string num = "";
for(int i = 0 ; i < s.size(); i++){
num += to_string(s[i] - 'a' + 1);
}
int transform;
while(k--){
transform = getSum(num);
num = to_string(transform);
}
return transform;
}
};