init commit

3sem/cnts/contest7/02.c

@@ -0,0 +1,54 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+enum
+{
+    THURSDAY = 4,
+    YEAR_OFFSET = 1900,
+    LAST_DIGIT_REM = 3,
+    GOOD_THURSDAY1 = 2,
+    GOOD_THURSDAY2 = 4
+};
+
+int
+main(int argc, char *argv[])
+{
+    int year;
+    if (scanf("%d", &year) != 1) {
+        fprintf(stderr, "Invalid input\n");
+
+        return 1;
+    }
+
+    struct tm t = {0};
+    t.tm_isdst = -1;
+    t.tm_mday = 1;
+    t.tm_year = year - YEAR_OFFSET;
+
+    int num_of_thursdays = 0, last_month = 0;
+
+    while (t.tm_year == year - YEAR_OFFSET) {
+        mktime(&t);
+
+        if (t.tm_mon != last_month) {
+            last_month = t.tm_mon;
+            num_of_thursdays = 0;
+        }
+
+        if (t.tm_wday == THURSDAY) {
+            num_of_thursdays++;
+
+            if (t.tm_mday % LAST_DIGIT_REM != 0 &&
+                (num_of_thursdays == GOOD_THURSDAY1 || num_of_thursdays == GOOD_THURSDAY2)) {
+                printf("%d %d\n", t.tm_mon + 1, t.tm_mday);
+            }
+
+            t.tm_mday += 7;
+        } else {
+            t.tm_mday++;
+        }
+    }
+
+    return 0;
+}