finish quiz 6

lab2/datalab-handout/bits.c

@@ -236,7 +236,11 @@ int isAsciiDigit(int x) {
  *   Rating: 3
  */
 int conditional(int x, int y, int z) {
-  return 2;
+  int signx = (!x << 31) >> 31; // if x == 0 signx 111, if x != 0 signx 00000
+  int ywhenx = (~signx) & y; // if signx 111 is 0
+  int zwhenx = (signx) & z;
+  int result = ywhenx | zwhenx;
+  return result;
 }
 /* 
  * isLessOrEqual - if x <= y  then return 1, else return 0