Sword refers to the clockwise printing matrix of OFFER (9 degrees OJ1391)

Description:

Enter a matrix and print each number in clockwise order from the external, for example, if you enter the following matrix:

1 2 3 4

5 6 7 8

9 10 11 12

13 14 15 16

The numbers 1, 2, 3, 4, 8, 12, 16, 15, 14, 13, 9, 5, 6, 7, 11, 10 are printed in sequence.

 

Input:

The input may contain multiple test examples. For each test case,

The first line of the input contains two integers m and n (1 <= m, n <= 1000): the dimension of the matrix is m rows and n columns.

In the next m row, each row contains n integers, indicating the elements of the matrix. The value range of each element a is (1 <= a <= 10000 ).

 

Output:

Output a line for each test case,

Each number is printed in clockwise order from the forward to the right, and each number is followed by a space.

 

Sample input:

4 41 2 3 45 6 7 89 10 11 1213 14 15 16

Sample output:

1 2 3 4 8 12 16 15 14 13 9 5 6 7 11 10 

Solution:

This questionThere is a pitfall, but it has been explained in the question that every number is followed by a space. Therefore, the last number also has a space..

The main idea is to adopt a layer-by-layer strip output. We mark the range of threshold_m and threshold_n in each row, and then call the output function by specifying the output vertex.

　　　　 threshold_n = n;        threshold_m = m;        i=0;        j=0;        while(i<threshold_m && j < threshold_n){            printMatrix(i,j);            i++;            j++;            threshold_n--;            threshold_m--;        }

 

void printMatrix(int m,int n){    int i=m,j=n;    for( ;j<threshold_n;j++){        printf("%d ",arr[i][j]);    }    j--;    for(i++;i<threshold_m;i++){        printf("%d ",arr[i][j]);    }    i--;    for(j--;j>=n && i!=m;j--){        printf("%d ",arr[i][j]);    }    j++;    for(i--;i>m && j!=threshold_n-1;i--){        printf("%d ",arr[i][j]);    }}

 

All code:

#include <stdio.h>#define MAXSIZE 1000int arr[MAXSIZE][MAXSIZE] = {0};int threshold_m = 0;int threshold_n = 0;void printMatrix(int m,int n);    int main(){    int m,n,i,j;    while(scanf("%d %d",&m,&n) != EOF  && n>=1 && n<=1000 && m>=1 && m<=1000){           for(i=0;    i<m; i++){            for(j=0;    j<n; j++)                scanf("%d",&arr[i][j]);        }        threshold_n = n;        threshold_m = m;        i=0;        j=0;        while(i<threshold_m && j < threshold_n){            printMatrix(i,j);            i++;            j++;            threshold_n--;            threshold_m--;        }        printf("\n");    }    return 0;}void printMatrix(int m,int n){    int i=m,j=n;    for( ;j<threshold_n;j++){        printf("%d ",arr[i][j]);    }    j--;    for(i++;i<threshold_m;i++){        printf("%d ",arr[i][j]);    }    i--;    for(j--;j>=n && i!=m;j--){        printf("%d ",arr[i][j]);    }    j++;    for(i--;i>m && j!=threshold_n-1;i--){        printf("%d ",arr[i][j]);    }}/**************************************************************    Problem: 1391    User: xhalo    Language: C    Result: Accepted    Time:560 ms    Memory:4820 kb****************************************************************/