Given a string S and a character C, return an array of integers representing the shortest distance from the character C in the string. javascript

class Solution {
public:
    vector<int> shortestToChar(string S, char C) {
        vector<int> r(S.size(), 0);
        int prev = -S.size();
        for (int i = 0; i < S.size(); ++ i) {
            if (S[i] == C) prev = i;
            r[i] = i - prev;
        }
        prev = INT_MAX;
        for (int i = S.size() - 1; i >= 0; -- i) {
            if (S[i] == C) prev = i;
            r[i] = min(r[i], prev - i);
        }
        return r;
    }
};class Solution {
public:
    vector<int> shortestToChar(string S, char C) {
        int n = S.size();
        vector<int> r(n, n);
        for (int i = 0; i < n; ++ i) {
            if (S[i] == C) r[i] = 0;
        }
        for (int i = 1; i < n; ++ i) {
            r[i] = min(r[i], r[i - 1] + 1);
        }
        for (int i = n - 2; i >= 0; -- i) {
            r[i] = min(r[i], r[i + 1] + 1);
        }
        return r;
    }
};