UniLecs #1. Unique symbols

unique_sym.py

def check_unique_symbols(string: str):
    """
    Check if in string unique symbol repeats. 
    """
    symbols = []
    for symbol in string:
        if symbol in symbols:
            return False
        else:
            symbols.append(symbol)
    return True

uniqueSym.c

#include <stdio.h>
#include <string.h>
#include <stdbool.h>

bool checkUniqueSymbols(char* string) {
  for (int i = 0; i < strlen(string); i++) {
    for (int j = i + 1; j < strlen(string); j++) {
      if (string[i] == string[j]) {
        return false;
      }
    }
  }
  return true;
}

int main(void) {
  char string[100];
  scanf("%[^\n]s", string);
  printf("%d\n", checkUniqueSymbols(string));
  return 0;
}

uniqueSym.go

package main

import "fmt"

func runeInSlice(a rune, list []rune) bool {
  // Check if rune in rune array
  for _, b := range list {
    if b == a {
      return true
    }
  }
    return false
}

func checkUniqueSymbols(str string) bool {
  // Check if in string unique symbol repeats. 
  var runes []rune
  for _, char := range str {
    if runeInSlice(char, runes) {
      return false
    } else {
      runes = append(runes, char)
    }
  }
  return true
}