[2300] CF1314D 随机化 二分图染色 DP

Author: EndlessCheng

main/1300-1399/1314D.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"bufio"
+	. "fmt"
+	"io"
+	"math/rand"
+	"time"
+)
+
+// github.com/EndlessCheng/codeforces-go
+func CF1314D(_r io.Reader, out io.Writer) {
+	rand.Seed(time.Now().UnixNano())
+	in := bufio.NewReader(_r)
+	min := func(a, b int) int {
+		if a > b {
+			return b
+		}
+		return a
+	}
+
+	var n, k int
+	Fscan(in, &n, &k)
+	dis := make([][]int, n)
+	for i := range dis {
+		dis[i] = make([]int, n)
+		for j := range dis[i] {
+			Fscan(in, &dis[i][j])
+		}
+	}
+
+	ans := int(1e9)
+	dp := make([]int, n)
+	color := make([]int, n)
+	for t := 5000; t > 0; t-- {
+		dp[0] = 0
+		for i := 1; i < n; i++ {
+			dp[i] = 1e9
+			color[i] = rand.Intn(2)
+		}
+		for i := 0; i < k; i++ {
+			for v, c := range color {
+				if c != i&1 {
+					dp[v] = 1e9
+					for from, c := range color {
+						if c == i&1 {
+							// dp[i][v] 表示走了 i 条边，当前在节点 v 时的最小花费，那么答案就是 dp[k][0]
+							// 其中第一维可以压缩掉
+							dp[v] = min(dp[v], dp[from]+dis[from][v])
+						}
+					}
+				}
+			}
+		}
+		ans = min(ans, dp[0])
+	}
+	Fprint(out, ans)
+}
+
+//func main() { CF1314D(os.Stdin, os.Stdout) }

main/1300-1399/1314D_test.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"github.com/EndlessCheng/codeforces-go/main/testutil"
+	"testing"
+)
+
+// CF1310D
+
+// https://codeforces.com/problemset/problem/1314/D
+// https://codeforces.com/problemset/status/1314/problem/D
+func TestCF1314D(t *testing.T) {
+	// just copy from website
+	rawText := `
+inputCopy
+5 8
+0 1 2 2 0
+0 0 1 1 2
+0 1 0 0 0
+2 1 1 0 0
+2 0 1 2 0
+outputCopy
+2
+inputCopy
+3 2
+0 1 1
+2 0 1
+2 2 0
+outputCopy
+3`
+	testutil.AssertEqualCase(t, rawText, 0, CF1314D)
+}