[2000] CF777E 栈+贪心

main/700-799/777E.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"bufio"
+	. "fmt"
+	"io"
+	"sort"
+)
+
+// github.com/EndlessCheng/codeforces-go
+func CF777E(_r io.Reader, out io.Writer) {
+	in := bufio.NewReader(_r)
+	var n int
+	Fscan(in, &n)
+	a := make([]struct{ r, R, h int }, n)
+	for i := range a {
+		Fscan(in, &a[i].r, &a[i].R, &a[i].h)
+	}
+	sort.Slice(a, func(i, j int) bool { a, b := a[i], a[j]; return a.R > b.R || a.R == b.R && a.r > b.r })
+
+	sum := int64(a[0].h)
+	ans := sum
+	s := []int{0}
+	for i := 1; i < n; i++ {
+		for len(s) > 0 && a[s[len(s)-1]].r >= a[i].R {
+			sum -= int64(a[s[len(s)-1]].h)
+			s = s[:len(s)-1]
+		}
+		s = append(s, i)
+		sum += int64(a[i].h)
+		if sum > ans {
+			ans = sum
+		}
+	}
+	Fprint(out, ans)
+}
+
+//func main() { CF777E(os.Stdin, os.Stdout) }

main/700-799/777E_test.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"github.com/EndlessCheng/codeforces-go/main/testutil"
+	"testing"
+)
+
+// https://codeforces.com/problemset/problem/777/E
+// https://codeforces.com/problemset/status/777/problem/E
+func TestCF777E(t *testing.T) {
+	// just copy from website
+	rawText := `
+inputCopy
+3
+1 5 1
+2 6 2
+3 7 3
+outputCopy
+6
+inputCopy
+4
+1 2 1
+1 3 3
+4 6 2
+5 7 1
+outputCopy
+4`
+	testutil.AssertEqualCase(t, rawText, 0, CF777E)
+}