Leetcode Longest Common Prefix problem solution in C

char * longestCommonPrefix(char ** strs, int strsSize){
    
    int min_str = 200;
    int index;
    
    if(strsSize == 0)
        return "";
    
    if(strsSize < 0 || strsSize > 200)
        return NULL;
                            
    //Find the shortest string
    for(int j=0; j<strsSize; j++){
        if(strlen(strs[j]) < min_str){
            min_str = strlen(strs[j]);
            index = j;
        }
    }
                                    
    for(int i=0; i<min_str; i++){
        for(int j=0; j<strsSize; j++){
            if(strs[index][i] != strs[j][i]){
                strs[index][i] = '\0';
                goto ret;
            }
        }
    }
ret:
    return strs[index];
}