[1800] CF1063B 结论题 01BFS

Author: EndlessCheng

main/1000-1099/1063B.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"bufio"
+	. "fmt"
+	"io"
+)
+
+// github.com/EndlessCheng/codeforces-go
+type pair63 struct{ x, y, l, r int }
+type deque63 struct{ l, r []pair63 }
+
+func (q deque63) empty() bool     { return len(q.l) == 0 && len(q.r) == 0 }
+func (q *deque63) pushL(v pair63) { q.l = append(q.l, v) }
+func (q *deque63) pushR(v pair63) { q.r = append(q.r, v) }
+func (q *deque63) popL() (v pair63) {
+	if len(q.l) > 0 {
+		q.l, v = q.l[:len(q.l)-1], q.l[len(q.l)-1]
+	} else {
+		v, q.r = q.r[0], q.r[1:]
+	}
+	return
+}
+
+func CF1063B(_r io.Reader, out io.Writer) {
+	in := bufio.NewReader(_r)
+	dir4 := []struct{ x, y, l, r int }{{x: -1}, {x: 1}, {0, -1, 1, 0}, {0, 1, 0, 1}}
+
+	var n, m, sx, sy, ll, rr, ans int
+	Fscan(in, &n, &m, &sx, &sy, &ll, &rr)
+	sx--
+	sy--
+	g := make([][]byte, n)
+	for i := range g {
+		Fscan(in, &g[i])
+	}
+
+	q := deque63{}
+	q.pushL(pair63{sx, sy, 0, 0})
+	g[sx][sy] = 0
+	for !q.empty() {
+		ans++
+		p := q.popL()
+		for _, d := range dir4 {
+			x, y, l, r := p.x+d.x, p.y+d.y, p.l+d.l, p.r+d.r
+			if 0 <= x && x < n && 0 <= y && y < m && l <= ll && r <= rr && g[x][y] == '.' {
+				g[x][y] = 0
+				p := pair63{x, y, l, r}
+				if d.y == 0 {
+					q.pushL(p)
+				} else {
+					q.pushR(p)
+				}
+			}
+		}
+	}
+	Fprint(out, ans)
+}
+
+//func main() { CF1063B(os.Stdin, os.Stdout) }

main/1000-1099/1063B_test.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"github.com/EndlessCheng/codeforces-go/main/testutil"
+	"testing"
+)
+
+// https://codeforces.com/problemset/problem/1063/B
+// https://codeforces.com/problemset/status/1063/problem/B
+func TestCF1063B(t *testing.T) {
+	// just copy from website
+	rawText := `
+inputCopy
+4 5
+3 2
+1 2
+.....
+.***.
+...**
+*....
+outputCopy
+10
+inputCopy
+4 4
+2 2
+0 1
+....
+..*.
+....
+....
+outputCopy
+7`
+	testutil.AssertEqualCase(t, rawText, 0, CF1063B)
+}