1105. Spiral Matrix (25)

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

#include<stdio.h>
#include<vector>
#include<algorithm>
#include<math.h>
using namespace std;
int ans[111][111];

bool cmp(int a,int b)
{
    return a > b;
}
int main()
{
    int len,tem;
    scanf("%d",&len);
    vector<int> vv;
    for(int i = 1 ;i <= len ;++i)
    {
        scanf("%d",&tem);
        vv.push_back(tem);
    }
    sort(vv.begin(),vv.end(),cmp);
    int n,m;
    n = sqrt((double)len);
    while(len % n != 0)
    {
        --n;
    }
    m = len / n;
    int high = 1, low = m, left = 1,right = n;
    int  x = 1,y = 1;
    for(int i = 0 ;i < len ;++i)
    {
        while(i < len && x <= right)
        {
            ans[y][x] = vv[i];
            ++i;
            ++x;
        }
        --x;
        ++y;
        ++high;
        while(i < len && y <= low)
        {
            ans[y][x] = vv[i];
            ++i;
            ++y;
        }
        --y;
        --x;
        --right;
        while(i < len && x >= left)
        {
            ans[y][x] = vv[i];
            ++i;
            --x;
        }
        ++x;
        --y;
        --low;
        while(i < len && y >= high)
        {
            ans[y][x] = vv[i];
            ++i;
            --y;
        }
        ++y;
        ++x;
        ++left;
        --i;
    }
    for(int i = 1 ;i <= m ;++i)
    {
        for(int k = 1 ;k <= n ;++k)
        {
            if(k == 1) printf("%d",ans[i][k]);
            else printf(" %d",ans[i][k]);
        }
        printf("
");
    }
    return 0;
}