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.
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.
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
题解：
#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;
const int N = 10010;
int n, w[N];
int main() {
cin >> n;
for (int i = 0; i < n; i++)
cin >> w[i];
sort(w, w + n, greater<int>());
int r, c;
for (int i = 1; i <= n / i; i++)
{
if (n%i == 0)
{
r = n / i;
c = i;
}
}
vector<vector<int>> res(r, vector<int>(c));
int dx[] = { -1,0,1,0 }, dy[] = { 0,1,0,-1 };
for (int i = 0, x = 0, y = 0, d = 1; i < n; i++)
{
res[x][y] = w[i];
int a = x + dx[d], b = y + dy[d];
if (a < 0 || a >= r || b < 0 || b >= c || res[a][b])
{
d = (d + 1) % 4;
a = x + dx[d], b = y + dy[d];
}
x = a, y = b;
}
for (int i = 0; i < r; i++)
{
cout << res[i][0];
for (int j = 1; j < c; j++)
cout << ' ' << res[i][j];
cout << endl;
}
return 0;
}
