[2100][1A] CF1593F 二染色 搜索

Author: EndlessCheng

main/1500-1599/1593F.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	. "fmt"
+	"io"
+)
+
+// github.com/EndlessCheng/codeforces-go
+func CF1593F(in io.Reader, out io.Writer) {
+	abs := func(x int) int {
+		if x < 0 {
+			return -x
+		}
+		return x
+	}
+
+	var T, n, ma, mb int
+	var s string
+	for Fscan(in, &T); T > 0; T-- {
+		Fscan(in, &n, &ma, &mb, &s)
+		minD, ans := n, "-1"
+		t := make([]byte, n)
+		vis := [40][40][40][41]bool{}
+		var f func(i, x, y, c int)
+		f = func(i, x, y, c int) {
+			if i == n {
+				if x == 0 && y == 0 && abs(n-c*2) < minD {
+					minD = abs(n - c*2)
+					ans = string(t)
+				}
+				return
+			}
+			if vis[i][x][y][c] {
+				return
+			}
+			vis[i][x][y][c] = true
+			t[i] = 'R'
+			f(i+1, (x*10+int(s[i]&15))%ma, y, c+1)
+			t[i] = 'B'
+			f(i+1, x, (y*10+int(s[i]&15))%mb, c)
+		}
+		f(0, 0, 0, 0)
+		Fprintln(out, ans)
+	}
+}
+
+//func main() { CF1593F(os.Stdin, os.Stdout) }

main/1500-1599/1593F_test.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"github.com/EndlessCheng/codeforces-go/main/testutil"
+	"testing"
+)
+
+// https://codeforces.com/problemset/problem/1593/F
+// https://codeforces.com/problemset/status/1593/problem/F
+func TestCF1593F(t *testing.T) {
+	// just copy from website
+	rawText := `
+inputCopy
+4
+5 3 13
+02165
+4 2 1
+1357
+8 1 1
+12345678
+2 7 9
+90
+outputCopy
+RBRBR
+-1
+BBRRRRBB
+BR`
+	testutil.AssertEqualCase(t, rawText, 0, CF1593F)
+}