fix quiz7

lab2/datalab-handout/bits.c

@@ -252,7 +252,7 @@ int conditional(int x, int y, int z) {
 int isLessOrEqual(int x, int y) {
   int signx = x >> 31;
   int signy = y >> 31;
-  int isnegpos = signx ^ signy & signx; // 0xFFFFF if signx = 1 sign y = 0
+  int isnegpos = (signx ^ signy) & (~signx); // 0xFFFFF if signx = 1 sign y = 0
   int sign1 = ~(1 << 31); // 01111111...111
   int absx = x & sign1;
   int absy = y & sign1;