1 files changed, 25 insertions, 0 deletions
diff --git a/2/3_int_arith/230.c b/2/3_int_arith/230.c
new file mode 100644
index 0000000..8bba282
--- /dev/null
+++ b/2/3_int_arith/230.c
@@ -0,0 +1,25 @@
+#include <limits.h>
+#include <stdio.h>
+
+int tadd_ok(int x, int y) {
+    int positive_overflow = x > 0 && y > 0 && x + y < 0;
+    int negative_overflow = x < 0 && y < 0 && x + y >= 0;
+    return !positive_overflow && !negative_overflow;
+}
+
+int tadd_buggy(int x, int y) {
+    int sum = x+y;
+    printf("sum: %d, sum-x: %d, sum-y: %d", sum, sum-x, sum-y);
+    return (sum-x == y) && (sum-y == x);
+}
+
+/* buggy */
+int tsub_ok(int x, int y) {
+    return tadd_ok(x, -y);
+}
+
+void main() {
+    printf("INT_MIN: %d, %d\n", -(INT_MIN), INT_MIN);
+    printf("result:  %d\n", tadd_ok(10, 100));
+    printf("result2: %d", tadd_buggy(INT_MAX, 1)); // The sum is a very negative number, when we take the difference with it's parts it just does a negative overflow to get the original parts back.
+}