team Activity - Strstr

strstr.cc

// First pass at writing C++... also probably should have checked the docs for some native find/includes/etc methods,
// but there's something kinda fun about brute forcing a solution first... 
// TODO: other early return cases? string methods to use instead? ew nested loop... 

class Solution {
public:
    int strStr(string haystack, string needle) {
        if (needle == "") {
            return 0;
        } else if (needle.length() > haystack.length()){
            return -1;  
        } else {
            return needleCheck(haystack, needle);
        }
    }
    
    int needleCheck(string haystack, string needle) {
        for (int i = 0; i < haystack.length(); i++) {
            if (haystack[i] == needle[0]) {
                // do some additional checks if there's character matches... 
                // ew - feels like there's a recursive or less nested way... 
                // or a curried approach? 
                bool found = true;
                for(int j = 0; j < needle.length(); j++) {
                    if (haystack[i+j] != needle[j]) {
                        found = false;
                        break;
                    }
                }
                if (found) {
                    return i;    
                }
            }
                
        }
        return -1;
    }
    
};

# --- Found on submissions --- 
# (ya gotta have an account and click into the time distribution) https://leetcode.com/submissions/detail/516402722/
# 0 ms submission
class Solution {
public:
    int strStr(string haystack, string needle) {
        if (needle == "") {
            return 0;
        }
        
        // ah... .size() - 
        if (haystack.size() < needle.size()) {
            return -1;
        }
        
        if (haystack.size() == needle.size()) {
            if (haystack == needle) {
                return 0;
            } else {
                return -1;
            }
        }
        
        size_t pos = haystack.find(needle);
        if (pos != string::npos) {
            return pos;
        } else {
            return -1;
        }
    }
};