完美矩形: N 个小矩形可以完美拼接成一个大矩形,不缺,不重
重点在于如何保证不缺和不重复

  1. 先对所有的输入进行遍历找到 最终的左下角,右上角
  2. 检查如果有超越,左右点的边界的 则舍弃
  3. 检查是否为完美矩形(除了标记,每个端点必然完全重合,而且是两次)
package main 
import (
    "fmt"
    "os"
    "bufio"
    "strconv"
    "strings"
)
type node struct {
    x1 int 
    y1 int
    x2 int 
    y2 int 
}
func main(){
    var n int 
    fmt.Scanf("%d",&n)
    arr := make([]node,n)
    scanner := bufio.NewScanner(os.Stdin)
    scanner.Split(bufio.ScanWords)

    for i:=0;i<n;i++{
        if scanner.Scan(){
            arr[i].x1 ,_ = strconv.Atoi(scanner.Text())
        }
        if scanner.Scan(){
            arr[i].y1 ,_ = strconv.Atoi(scanner.Text())
        }
        if scanner.Scan(){
            arr[i].x2 ,_ = strconv.Atoi(scanner.Text())
        }
        if scanner.Scan(){
            arr[i].y2 ,_ = strconv.Atoi(scanner.Text())
        }
    }
    bOk := helper(arr,n)
    if bOk == true {
        fmt.Println("Yes")
    }else{
        fmt.Println("No")
    }
    return 

}
func helper(arr []node ,n int) bool{
    index1,index2 := 0,0
    //求出边界
    for i:=0;i<n;i++{
        //找打了更小的左下角了
        if arr[index1].x1 >= arr[i].x1 && arr[index1].y1 >= arr[i].y1{
            index1 = i
        }
        //找到了更大的右上角了
        if arr[index2].x2 <= arr[i].x2 && arr[index2].y2 <=arr[i].y2 {
            index2 = i
        }
    }
    //可以用或的关系先干掉一波
    for i:=0;i<n;i++{
        bOk := arr[i].x1 <arr[index1].x1 || 
        arr[i].y1 < arr[index1].y1 ||
        arr[i].x2 > arr[index2].x2 ||
        arr[i].y2 > arr[index2].y2 
        if bOk == true {
            return false
        }
    }
    //将每个四边形的四个点都进行一下统计
    tmpmap := make(map[string]int )
    for i:=0;i<n;i++{
        A := strconv.Itoa(arr[i].x1) + "-" + strconv.Itoa(arr[i].y1)
        B := fmt.Sprintf("%d-%d",arr[i].x1,arr[i].y2)
        C := fmt.Sprintf("%d-%d",arr[i].x2,arr[i].y2)
        D := fmt.Sprintf("%d-%d",arr[i].x2,arr[i].y1)

        tmpmap[A]++
        tmpmap[B]++
        tmpmap[C]++
        tmpmap[D]++

    }
    //对统计结果进行计算
    for key,val := range tmpmap {
        //有偶数个重合的可以直接跳过
        if val % 2 == 0 {
            continue 
        }

        //将key 进行拆分
        tmp := strings.Split(key,"-")
        //fmt.Println(tmp,key)
        x1,_ := strconv.Atoi(tmp[0])
        y1,_ := strconv.Atoi(tmp[1])
        if x1 == arr[index1].x1 || x1== arr[index2].x1 || y1==arr[index1].y1 || y1== arr[index2].y2{
            continue;
        }
        return false 
     }
    return true


}