AtCoder Contest 053 by go lang

a.go

package main

import (
	"fmt"
)

func main() {
	var a int
	var answer string
	fmt.Scan(&a)

	if a < 1200 {
		answer = "ABC"
	} else {
		answer = "ARC"
	}

	fmt.Println(answer)
}

b.go

package main

import (
	"fmt"
	"strings"
)

func main() {
	var s string
	fmt.Scan(&s)

	var aIndex = strings.Index(s, "A")
	var zIndex = strings.LastIndex(s, "Z")

	var answer = zIndex - aIndex + 1
	fmt.Println(answer)
}

c.go

package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)
	var quotient = n / 11
	var remainder = n % 11
	var c int
	switch {
	case remainder == 0:
		c = 0
	case remainder <= 6:
		c = 1
	case remainder > 6:
		c = 2
	}
	var answer = quotient*2 + c
	fmt.Println(answer)
}

d.go

package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)
	a := make([]int, n)
	for i := range a {
		fmt.Scan(&a[i])
	}
	counter := make(map[int]int)
	for _, v := range a {
		counter[v]++
	}
	evenCount := 0
	for _, v := range counter {
		if v%2 == 0 {
			evenCount++
		}
	}
	answer := len(counter)
	if evenCount%2 == 1 {
		answer--
	}
	fmt.Println(answer)
}

e.go

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

var sc = bufio.NewScanner(os.Stdin)

// Binary indexed tree

type BITree struct {
	bit []int
	M int
}

func newBITree(m int) *BITree {
	b := new(BITree)
	b.M = m
	b.bit = make([]int, m + 1)
	return b
}

func (b BITree) sum(i int) int {
	if (i <= 0) {
		return 0
	}
	return b.bit[i] + b.sum(i - (-i & i))
}

func (b BITree) add(i int, x int) {
	if (i > b.M) {
		return
	}
	b.bit[i] += x
	b.add(i + (-i & i), x)
}

type Section struct {
	start int
	end int
}

func main() {
	N, M, l, r := scan()

	// 区間[l,r]を長さによって分類する
	sectionsGroup := make([][]Section, M + 1)
	for i := 0; i <= M; i++ {
		sectionsGroup[i] = make([]Section, 0)
	}
	for n := 0; n < N; n++ {
		length := r[n] - l[n] + 1
		section := Section{
			start: l[n],
			end: r[n],
		}
		sectionsGroup[length] = append(sectionsGroup[length], section)
	}

	// 必ず通る区間たち
	base := N
	// Binary indexed tree
	bit := newBITree(M+2)

	answers := make([]int, M + 1)

	// BIT使って頑張る
	for d := 1; d <= M; d++ {
		sections := sectionsGroup[d - 1]
		for _, section := range sections {
			start := section.start
			end := section.end
			bit.add(start, 1)
			bit.add(end + 1, -1)
		}
		base -= len(sections)
		answers[d] = base
		for pos := 0; pos <= M; pos += d {
			answers[d] += bit.sum(pos)
		}
	}

	for d := 1; d <= M; d++ {
		fmt.Println(answers[d])
	}
}


func scan() (int, int, []int, []int) {
	var N, M int
	sc.Scan()
	nm := strings.Split(sc.Text(), " ")
	N, _ = strconv.Atoi(nm[0])
	M, _ = strconv.Atoi(nm[1])
	l := make([]int, N)
	r := make([]int, N)
	for i := 0; i < N; i++ {
		sc.Scan()
		lr := strings.Split(sc.Text(), " ")
		l[i], _ = strconv.Atoi(lr[0])
		r[i], _ = strconv.Atoi(lr[1])
	}
	return N, M, l, r
}