Repeated characters in string-CodePudding

I am trying to create a function to identify whether or not a character is repeated in a given string.

int checkrow(char* row) {
    int count, r;
    for(int i = 0; i < strlen(row); i  ) {
        count = 1;
        for(int j = i   1; j < strlen(row); j  ) {
            if(row[i] == row[j]) {
                count = count   1;
            }
        }
        if(count > 1 ) {
            r = 0;
        }
        else {
            r = 1;
        }
    }
    return r;
}

This is my function at the moment, I am not getting an error or warning messages, but it is not identifying repeated characters.

I am very new to C and any help would be appreciated!

CodePudding user response：

For each character you test, you set r to whether that character is repeated. So if the first character is repeated you set r = 0, but then if the second character is not repeated, you set r = 1.

You don't need to test every character. As soon you find a repeated character, you can return 0. If you get to the end of the loop, nothing was repeated, so you return 1.

int checkrow(char* row) {
    for(size_t i = 0; i < strlen(row); i  ) {
        for(size_t j = i   1; j < strlen(row); j  ) {
            if(row[i] == row[j]) {
                return 0;
            }
        }
    }
    return 1;
}