aaa

src/codeforces/set1/set16/set165/set1654/f/solution.go

@@ -0,0 +1,129 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"sort"
+)
+
+func main() {
+	reader := bufio.NewReader(os.Stdin)
+
+	n := readNum(reader)
+	s := readString(reader)
+	res := solve(n, s)
+	fmt.Println(res)
+}
+
+func readString(reader *bufio.Reader) string {
+	s, _ := reader.ReadString('\n')
+	for i := 0; i < len(s); i++ {
+		if s[i] == '\n' || s[i] == '\r' {
+			return s[:i]
+		}
+	}
+	return s
+}
+
+func normalize(s string) string {
+
+	for i := len(s); i > 0; i-- {
+		if s[i-1] >= 'a' && s[i-1] <= 'z' {
+			return s[:i]
+		}
+	}
+	return ""
+}
+
+func readInt(bytes []byte, from int, val *int) int {
+	i := from
+	sign := 1
+	if bytes[i] == '-' {
+		sign = -1
+		i++
+	}
+	tmp := 0
+	for i < len(bytes) && bytes[i] >= '0' && bytes[i] <= '9' {
+		tmp = tmp*10 + int(bytes[i]-'0')
+		i++
+	}
+	*val = tmp * sign
+	return i
+}
+
+func readNum(reader *bufio.Reader) (a int) {
+	bs, _ := reader.ReadBytes('\n')
+	readInt(bs, 0, &a)
+	return
+}
+
+func readTwoNums(reader *bufio.Reader) (a int, b int) {
+	res := readNNums(reader, 2)
+	a, b = res[0], res[1]
+	return
+}
+
+func readThreeNums(reader *bufio.Reader) (a int, b int, c int) {
+	res := readNNums(reader, 3)
+	a, b, c = res[0], res[1], res[2]
+	return
+}
+
+func readNNums(reader *bufio.Reader, n int) []int {
+	res := make([]int, n)
+	x := 0
+	bs, _ := reader.ReadBytes('\n')
+	for i := 0; i < n; i++ {
+		for x < len(bs) && (bs[x] < '0' || bs[x] > '9') && bs[x] != '-' {
+			x++
+		}
+		x = readInt(bs, x, &res[i])
+	}
+	return res
+}
+
+func solve(n int, s string) string {
+	a := make([]int, 1<<n)
+	h := 1 << n
+	for i := 0; i < h; i++ {
+		a[i] = i
+	}
+
+	sort.Slice(a, func(i, j int) bool {
+		return s[a[i]] < s[a[j]]
+	})
+
+	v := make([]int, h)
+	for i := 1; i < h; i++ {
+		v[a[i]] = v[a[i-1]]
+		if s[a[i]] != s[a[i-1]] {
+			v[a[i]]++
+		}
+	}
+
+	tmp := make([]int, h)
+
+	for k := 1; k < h; k <<= 1 {
+		cmp := func(i, j int) bool {
+			if v[a[i]] == v[a[j]] {
+				return v[a[i]^k] < v[a[j]^k]
+			}
+			return v[a[i]] < v[a[j]]
+		}
+		sort.Slice(a, cmp)
+		tmp[a[0]] = 0
+		for i := 1; i < h; i++ {
+			tmp[a[i]] = tmp[a[i-1]]
+			if cmp(i-1, i) {
+				tmp[a[i]]++
+			}
+		}
+		copy(v, tmp)
+	}
+	buf := make([]byte, h)
+	for i := 0; i < h; i++ {
+		buf[i] = s[i^a[0]]
+	}
+	return string(buf)
+}

src/codeforces/set1/set16/set165/set1654/f/solution_test.go

@@ -0,0 +1,39 @@
+package main
+
+import "testing"
+
+func runSample(t *testing.T, n int, s string, expect string) {
+	res := solve(n, s)
+
+	if res != expect {
+		t.Fatalf("Sample expect %s, but got %s", expect, res)
+	}
+}
+
+func TestSample1(t *testing.T) {
+	n := 2
+	s := "acba"
+	expect := "abca"
+	runSample(t, n, s, expect)
+}
+
+func TestSample2(t *testing.T) {
+	n := 3
+	s := "bcbaaabb"
+	expect := "aabbbcba"
+	runSample(t, n, s, expect)
+}
+
+func TestSample3(t *testing.T) {
+	n := 4
+	s := "bdbcbccdbdbaaccd"
+	expect := "abdbdccacbdbdccb"
+	runSample(t, n, s, expect)
+}
+
+func TestSample5(t *testing.T) {
+	n := 5
+	s := "ccfcffccccccffcfcfccfffffcccccff"
+	expect := "cccccffffcccccffccfcffcccccfffff"
+	runSample(t, n, s, expect)
+}