CF1931D

main/1900-1999/1931D.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"bufio"
+	. "fmt"
+	"io"
+)
+
+// https://space.bilibili.com/206214
+func cf1931D(_r io.Reader, _w io.Writer) {
+	in := bufio.NewReader(_r)
+	out := bufio.NewWriter(_w)
+	defer out.Flush()
+
+	var T, n, x, y, v int
+	for Fscan(in, &T); T > 0; T-- {
+		Fscan(in, &n, &x, &y)
+		ans := 0
+		type pair struct{ x, y int }
+		cnt := map[pair]int{}
+		for ; n > 0; n-- {
+			Fscan(in, &v)
+			ans += cnt[pair{(x - v%x) % x, v % y}]
+			cnt[pair{v % x, v % y}]++
+		}
+		Fprintln(out, ans)
+	}
+}
+
+//func main() { cf1931D(os.Stdin, os.Stdout) }

main/1900-1999/1931D_test.go

@@ -0,0 +1,39 @@
+// Generated by copypasta/template/generator_test.go
+package main
+
+import (
+	"github.com/EndlessCheng/codeforces-go/main/testutil"
+	"testing"
+)
+
+// https://codeforces.com/contest/1931/problem/D
+// https://codeforces.com/problemset/status/1931/problem/D
+func Test_cf1931D(t *testing.T) {
+	testCases := [][2]string{
+		{
+			`7
+6 5 2
+1 2 7 4 9 6
+7 9 5
+1 10 15 3 8 12 15
+9 4 10
+14 10 2 2 11 11 13 5 6
+9 5 6
+10 7 6 7 9 7 7 10 10
+9 6 2
+4 9 7 1 2 2 13 3 15
+9 2 3
+14 6 1 15 12 15 8 2 15
+10 5 7
+13 3 3 2 12 11 3 7 13 14`,
+			`2
+0
+1
+3
+5
+7
+0`,
+		},
+	}
+	testutil.AssertEqualStringCase(t, testCases, 0, cf1931D)
+}