1105. Spiral Matrix

1105. Spiral Matrix (25)

时间限制

150 ms

内存限制

65536 kB

代码长度限制

16000 B

判题程序

Standard

作者

CHEN, Yue

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 mrows 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<iostream>
#include<vector>
#include<algorithm>
#include<cmath>
#include<cstring>
using namespace std;

bool cmp(const int &a,const int &b){
  return a>b;
}

int cal(int x){
  int y = sqrt(x);
  while(y>0){
    if(x%y == 0)
      return y;
    --y;
  }
  return 1;
}  

int main(){
  int n,a,flag[105][105],x,y,cnt = 0,num[105][105],sx = 0,sy = 0;
  vector<int> res;
  cin>>n;
  y = cal(n);
  x = n/y;
  memset(flag,-1,sizeof(flag));
  for(int i = 0;i<x;++i)
    for(int j = 0;j<y;++j)
      flag[i][j] = 0;
  for(int i = 0;i<n;++i){
    cin>>a;
    res.push_back(a);
  }  
  sort(res.begin(),res.end(),cmp);
  while(cnt<n){
    while(sy<y && flag[sx][sy] != -1){
      num[sx][sy] = res[cnt++];
      flag[sx][sy] = -1;
      ++sy;
    }
    --sy;
    ++sx;
    while(sx<x && flag[sx][sy] != -1){
      num[sx][sy] = res[cnt++];
      flag[sx][sy] = -1;
      ++sx;
    }
    --sx;
    --sy;
    while(sy>=0 && flag[sx][sy] != -1){
      num[sx][sy] = res[cnt++];
      flag[sx][sy] = -1;
      --sy;
    }
    ++sy;
    --sx;
    while(sx>=0 && flag[sx][sy] != -1){
      num[sx][sy] = res[cnt++];
      flag[sx][sy] = -1;
      --sx;
    }
    ++sx;
    ++sy;
  }
  for(int i = 0;i<x;++i){
    cout<<num[i][0];
    for(int j = 1;j<y;++j)
      cout<<" "<<num[i][j];
    cout<<endl;
  }
  return 0;
}