added function to convert int from 0 - 3 into binary string

src/conversionOfNumbers/conversionOfNumbers.c

@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+char* convertIntToBinaryStr(int input){
+    if(input > 3 || input < 0) return NULL;
+    int length = 2;
+    int rest;
+    char* result = (char*)malloc(sizeof(char) * length + 1);
+    int index = length - 1;
+    do{
+        rest = input % 2;
+        input /= 2;
+        if(rest == 1) result[index] = '1';
+        if(rest == 0) result[index] = '0';
+        index--; 
+    }while(input != 0);
+    result[length] = '\0';
+    return result;
+}