1105 Spiral Matrix(32行代码+详细注释)

分数 25

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作者 CHEN, Yue

单位 浙江大学

This time your job is to fill a sequence of N positive integers into a spiral matrix in non-increasing order. A spiral matrix is filled in from the first element at the upper-left corner, then move in a clockwise spiral. The matrix has m rows and n columns, where m and n satisfy the following: m×n must be equal to N; m≥n; and m−n is the minimum of all the possible values.

Input Specification:

Each input file contains one test case. For each case, the first line gives a positive integer N. Then the next line contains N positive integers to be filled into the spiral matrix. All the numbers are no more than 104. The numbers in a line are separated by spaces.

Output Specification:

For each test case, output the resulting matrix in m lines, each contains n numbers. There must be exactly 1 space between two adjacent numbers, and no extra space at the end of each line.

Sample Input:

12
37 76 20 98 76 42 53 95 60 81 58 93

Sample Output:

98 95 93
42 37 81
53 20 76
58 60 76

代码长度限制

16 KB

时间限制

200 ms

内存限制

64 MB

#include
using namespace std;
int main(){
    int n;
    cin>>n;
    int r,c,a[n];
    for(int i=0;i>a[i];
    sort(a,a+n,greater());//从大到小排序 
    for(int i=1;i<=n/i;i++){//获得符合条件的行和列 
        if(n%i==0){
            r=n/i;
            c=i;
        }
    }
    int dx[4]={0,1,0,-1},dy[4]={1,0,-1,0};//分别对应右，下，左，上 
    vector>res(r,vector(c));//二维动态数组 
    for(int i=0,x=0,y=0,d=0;i         res[x][y]=a[i];//每次先赋值 
        int tx=x+dx[d],ty=y+dy[d];//获取当前下标的下一个下标 
        if(tx<0||tx>r-1||ty<0||ty>c-1||res[tx][ty]){//若下一个下标不合法 
            d=(d+1)%4;//换个方向 
            tx=x+dx[d],ty=y+dy[d];//重新获取下标 
        }
        x=tx,y=ty;//获取下一个下标 
    }
    for(int i=0;i         cout<         for(int j=1;j         cout<     }
    return 0;
}