init commit

3sem/cnts/contest7/01-old.c

@@ -0,0 +1,56 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <linux/limits.h>
+#include <stdint.h>
+#include <string.h>
+
+int
+main(int argc, char *argv[])
+{
+    const char const_str[] = "18446744073709551616";
+
+    char tmp_str[PATH_MAX];
+
+    while (scanf("%s", tmp_str) == 1) {
+        int64_t res = 0;
+        uint64_t base = 1;
+
+        int is_overflow = 0;
+
+        for (int i = strlen(tmp_str) - 1; i >= 0; i--) {
+            char ch = tmp_str[i];
+
+            if (ch == 'a') {
+                if (__builtin_sub_overflow(res, base, &res)) {
+                    is_overflow = 1;
+
+                    break;
+                }
+            } else if (ch == '1') {
+                if (__builtin_add_overflow(res, base, &res)) {
+                    is_overflow = 1;
+
+                    break;
+                }
+            } else if (ch != '0') {
+                fprintf(stderr, "Invalid input\n");
+
+                return 1;
+            }
+
+            if (__builtin_mul_overflow(base, 3, &base) && i != 0) {
+                is_overflow = 1;
+
+                break;
+            }
+        }
+
+        if (is_overflow) {
+            printf("%s\n", const_str);
+        } else {
+            printf("%lld\n", res);
+        }
+    }
+
+    return 0;
+}