implemented binaryStrLen function into convertIntToBinaryStr

src/conversionOfNumbers/conversionOfNumbers.c

@@ -20,8 +20,7 @@ int binaryStrLen(int input){
 }
 
 char* convertIntToBinaryStr(int input){
-    if(input > 3 || input < 0) return NULL;
-    int length = 2;
+    int length = binaryStrLen(input);
     int rest;
     char* result = (char*)malloc(sizeof(char) * length + 1);
     result[length] = '\0';