1.启动多任务排序
拓扑排序
每次选入度为0的点
对每次选的点进行排序
package main
import (
"bufio"
"fmt"
"os"
"slices"
"strings"
)
func main() {
scanner := bufio.NewScanner(os.Stdin)
scanner.Scan()
text := scanner.Text()
relations := strings.Split(text, " ")
inNum := make(map[string]int)
NodeEdge := make(map[string][]string)
for i := 0; i < len(relations); i++ {
parts:=strings.Split(relations[i],"->")
r := string(parts[0])
l := string(parts[1])
inNum[r]++
if _, ok := inNum[l]; !ok {
inNum[l] = 0
}
NodeEdge[l] = append(NodeEdge[l], r)
}
//fmt.Println(inNum)
queue := []string{}
for k, v := range inNum {
//fmt.Println("=====", string(k+'A'))
if v == 0 {
queue = append(queue, k)
//fmt.Println(string(r+'A'), "---r")
}
}
ans := []string{}
for len(queue) > 0 {
slices.Sort(queue)
tmp := []string{}
for i := 0; i < len(queue); i++ {
ans = append(ans, queue[i])
for _, r := range NodeEdge[queue[i]] {
inNum[r]--
if inNum[r] == 0 {
//fmt.Println("+++", r)
tmp = append(tmp, r)
}
}
}
queue = tmp
}
fmt.Println(strings.Join(ans, " "))
}
2.欢乐周末
package main
import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
)
var n, m int
type pair struct{ x, y int }
var visit1 [][]bool
var visit2 [][]bool
var grid [][]int
var start []pair
var dst []pair
func main() {
scanner := bufio.NewScanner(os.Stdin)
scanner.Scan()
input := scanner.Text()
relations := strings.Split(input, " ")
n, _ = strconv.Atoi(relations[0])
m, _ = strconv.Atoi(relations[1])
grid = make([][]int, n)
visit1 = make([][]bool, n)
visit2 = make([][]bool, n)
for i := 0; i < n; i++ {
scanner.Scan()
input = scanner.Text()
line := strings.Split(input, " ")
grid[i] = make([]int, m)
visit1[i] = make([]bool, m)
visit2[i] = make([]bool, m)
for j := 0; j < m; j++ {
grid[i][j], _ = strconv.Atoi(line[j])
if grid[i][j] == 2 {
start = append(start, pair{i, j})
}
if grid[i][j] == 3 {
dst = append(dst, pair{i, j})
}
}
}
bfs(start[0].x, start[0].y, visit1)
bfs(start[1].x, start[1].y, visit2)
ans := 0
for _, v := range dst {
//fmt.Println(v)
if visit1[v.x][v.y] && visit2[v.x][v.y] {
ans++
}
}
fmt.Println(ans)
}
func bfs(i, j int, visit [][]bool) {
queue := []pair{}
queue = append(queue, pair{i, j})
//入队时就标记为true
visit[i][j] = true
for len(queue) > 0 {
tmp := []pair{}
for i := 0; i < len(queue); i++ {
now := queue[i]
dx := []int{1, 0, -1, 0}
dy := []int{0, 1, 0, -1}
for k := 0; k < 4; k++ {
nx := dx[k] + now.x
ny := dy[k] + now.y
if nx >= 0 && ny >= 0 && nx < n && ny < m && grid[nx][ny] != 1 && !visit[nx][ny] {
tmp = append(tmp, pair{nx, ny})
visit[nx][ny] = true
}
}
}
queue = tmp
}
}
3.返回矩阵中非1的元素个数
package main
import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
)
type pair struct{ x, y int }
var n, m int
// var visit [][]bool
var grid [][]int
func main() {
scanner := bufio.NewScanner(os.Stdin)
scanner.Scan()
text := scanner.Text()
line := strings.Split(text, " ")
n, _ = strconv.Atoi(line[0])
m, _ = strconv.Atoi(line[1])
grid = make([][]int, n)
//visit = make([][]bool, n)
for i := 0; i < n; i++ {
scanner.Scan()
text = scanner.Text()
line = strings.Split(text, " ")
grid[i] = make([]int, m)
//visit[i] = make([]bool, m)
for j := 0; j < m; j++ {
grid[i][j], _ = strconv.Atoi(line[j])
}
}
bfs(0, 0)
ans := 0
for i := 0; i < n; i++ {
//fmt.Println(grid[i])
for j := 0; j < m; j++ {
if grid[i][j] != 1 {
ans++
}
}
}
fmt.Println(ans)
}
func bfs(i int, j int) {
grid[i][j] = 1
queue := []pair{}
queue = append(queue, pair{i, j})
for len(queue) > 0 {
dx := []int{1, 0, -1, 0}
dy := []int{0, 1, 0, -1}
tmp := []pair{}
for i := 0; i < len(queue); i++ {
now := queue[i]
//fmt.Println("now", now.x, now.y)
for k := 0; k < 4; k++ {
nx := dx[k] + now.x
ny := dy[k] + now.y
//fmt.Println("nx,ny", nx, ny)
if nx >= 0 && ny >= 0 && nx < n && ny < m && grid[nx][ny] == 0 {
grid[nx][ny] = 1
//fmt.Println("add:", nx, ny)
tmp = append(tmp, pair{nx, ny})
//fmt.Println(tmp)
}
}
}
queue = tmp
//fmt.Println("queue", queue, len(queue))
}
}
4. 爱吃蟠桃的孙悟空
package main
import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
)
var nums []int
func main() {
scanner := bufio.NewScanner(os.Stdin)
scanner.Scan()
text := scanner.Text()
line := strings.Split(text, " ")
for i := 0; i < len(line); i++ {
num, _ := strconv.Atoi(line[i])
nums = append(nums, num)
}
//fmt.Println("nums", nums)
scanner.Scan()
text = scanner.Text()
time, _ := strconv.Atoi(text)
l, r := 1, 100010
for l < r {
mid := (l + r) >> 1
if check(mid) <= time {
r = mid
} else {
l = mid + 1
}
//fmt.Println("l,r", l, r)
}
if check(l) <= time {
fmt.Println(l)
} else {
fmt.Println(0)
}
//fmt.Println("+++", check(1))
}
func check(k int) int {
ans := 0
//注意这里
tmp := make([]int, len(nums))
copy(tmp, nums)
for i := 0; i < len(tmp); i++ {
for tmp[i] > 0 {
//fmt.Println("tmp:", tmp[i])
ans++
//fmt.Println("ans", ans)
tmp[i] -= k
}
}
return ans
}
5.矩阵匹配
匈牙利算法
package main
import (
"bufio"
"fmt"
"math"
"os"
"strconv"
"strings"
)
var (
n, m, k int
nums [][]int
match []int
visit []bool
)
func main() {
scanner := bufio.NewScanner(os.Stdin)
scanner.Scan()
text := scanner.Text()
line := strings.Split(text, " ")
n, _ = strconv.Atoi(line[0])
m, _ = strconv.Atoi(line[1])
k, _ = strconv.Atoi(line[2])
nums = make([][]int, n)
minNum := math.MaxInt
maxNum := math.MinInt
for i := 0; i < n; i++ {
scanner.Scan()
text = scanner.Text()
line = strings.Split(text, " ")
nums[i] = make([]int, m)
for j := 0; j < m; j++ {
nums[i][j], _ = strconv.Atoi(line[j])
minNum = min(minNum, nums[i][j])
maxNum = max(maxNum, nums[i][j])
}
}
l, r := minNum, maxNum
for l <= r {
mid := (l + r) >> 1
if valid(mid) >= n-k+1 {
r=mid-1
} else {
l = mid+1
}
}
fmt.Println(r+1)
}
func valid(maxValue int) int {
match = make([]int, m)
for i := 0; i < m; i++ {
match[i] = -1
}
cnt := 0
for i := 0; i < n; i++ {
visit = make([]bool, m)
if dfs(i, maxValue) {
cnt++
}
}
return cnt
}
func dfs(i int, maxValue int) bool {
for j := 0; j < m; j++ {
if !visit[j] && nums[i][j] <= maxValue {
visit[j] = true
if match[j] == -1 || dfs(match[j], maxValue) {
match[j] = i
return true
}
}
}
return false
}
6.荒岛求生
注意特殊情况，数字个数=0或>30000或者数字=0
从左往右遍历
积累Right的力量，算往左的人走能活几个
从右往左遍历
积累Left的力量，算往右的人走能活几个
ans=左边活的人+右边活的人
package main
import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
)
func main() {
var nums []int
scanner := bufio.NewScanner(os.Stdin)
scanner.Scan()
text := scanner.Text()
line := strings.Split(text, " ")
n := len(line)
if n > 30000 || n == 0 {
fmt.Println(-1)
return
}
for i := 0; i < n; i++ {
x, _ := strconv.Atoi(line[i])
if x==0 {
fmt.Println(-1)
return
}
nums = append(nums, x)
}
sumRight := 0
cnt := 0
for i := 0; i < n; i++ {
if nums[i] > 0 {
sumRight += nums[i]
} else {
numValue := -nums[i]
if numValue > sumRight {
cnt++
sumRight = 0
} else {
sumRight -= numValue
}
}
}
sumLeft := 0
for i := n - 1; i >= 0; i-- {
if nums[i] < 0 {
sumLeft += -nums[i]
} else {
if nums[i] > sumLeft {
sumLeft = 0
cnt++
} else {
sumLeft -= nums[i]
}
}
}
fmt.Println(cnt)
}
7.无向图染色
package main
import "fmt"
type pair struct{ x, y int }
func main() {
var n, m int
fmt.Scan(&n, &m)
if m == 0 {
fmt.Println(1 << n)
return
}
edge := []pair{}
for i := 0; i < m; i++ {
var x, y int
fmt.Scan(&x, &y)
edge = append(edge, pair{x, y})
}
ans := 0
for i := 0; i < 1<<n; i++ {
flag := true
for j := 0; j < m; j++ {
x, y := edge[j].x, edge[j].y
if i>>(x-1)&1 == 1 && i>>(y-1)&1 == 1 {
flag = false
break
}
}
if flag {
ans++
}
}
fmt.Println(ans)
}
