【Leetcode_easy】821. Shortest Distance to a Character

problem

821. Shortest Distance to a Character

solution1:

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

 solution2:

class Solution {
public:
    vector<int> shortestToChar(string S, char C) {
        int n = S.size();
        vector<int> res(n, n);
        int pos = -n;//errr...
        for(int i=0; i<n; ++i) 
        {
            if(S[i]==C) pos = i;
            res[i] = min(res[i], abs(i-pos));
        }
        for(int i=n-1; i>=0; --i) 
        {
            if(S[i]==C) pos = i;
            res[i] = min(res[i], abs(i-pos));
        }
        return res;
    }
};

参考

1. Leetcode_easy_821. Shortest Distance to a Character;

2. Discuss;

3. grandyang;

完