/in/foo.c: In function 'main':
/in/foo.c:6:2: warning: implicit declaration of function 'scanf_s'; did you mean 'scanf'? [-Wimplicit-function-declaration]
  scanf_s("%d %d %d", &x1, &x2, &x3);
  ^~~~~~~
  scanf
/in/foo.c:9:13: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
   if (((a&b == x1) && (a | b == x2) && (a == x3)) == 1)
           ~~^~~~~
/in/foo.c:9:30: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
   if (((a&b == x1) && (a | b == x2) && (a == x3)) == 1)
                            ~~^~~~~
/in/foo.c:11:13: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
   if (((a&b == x1) && (a | b == x3) && (a == x2)) == 1)
           ~~^~~~~
/in/foo.c:11:30: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
   if (((a&b == x1) && (a | b == x3) && (a == x2)) == 1)
                            ~~^~~~~
/in/foo.c:13:13: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
   if (((a&b == x2) && (a | b == x1) && (a == x3)) == 1)
           ~~^~~~~
/in/foo.c:13:30: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
   if (((a&b == x2) && (a | b == x1) && (a == x3)) == 1)
                            ~~^~~~~
/in/foo.c:15:13: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
   if (((a&b == x2) && (a | b == x3) && (a == x1)) == 1)
           ~~^~~~~
/in/foo.c:15:30: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
   if (((a&b == x2) && (a | b == x3) && (a == x1)) == 1)
                            ~~^~~~~
/in/foo.c:17:13: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
   if (((a&b == x3) && (a | b == x2) && (a == x1)) == 1)
           ~~^~~~~
/in/foo.c:17:30: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
   if (((a&b == x3) && (a | b == x2) && (a == x1)) == 1)
                            ~~^~~~~
/in/foo.c:19:13: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
   if (((a&b == x3) && (a | b == x1) && (a == x2)) == 1)
           ~~^~~~~
/in/foo.c:19:30: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
   if (((a&b == x3) && (a | b == x1) && (a == x2)) == 1)
                            ~~^~~~~
/in/foo.c:9:10: warning: 'a' is used uninitialized in this function [-Wuninitialized]
   if (((a&b == x1) && (a | b == x2) && (a == x3)) == 1)
        ~~^~~~~~~~~
/tmp/ccFK29Im.o: In function `main':
foo.c:(.text.startup+0x1d): undefined reference to `scanf_s'
collect2: error: ld returned 1 exit status