剑指Offer18 顺时针打印矩阵

Posted 2020-08-05 Juntaran

/*************************************************************************
    > File Name: 18_PrintMatrixClock.c
    > Author: Juntaran
    > Mail: [email protected]
    > Created Time: 2016年08月30日 星期二 17时32分28秒
 ************************************************************************/

#include <stdio.h>
#include <stdlib.h>

#define COL 4
#define ROW 1

void PrintMatrixCircle(int nums[][COL], int col, int row, int start)
{
    // 从左到右打一行
    for (int i = start; i < col-start; ++i)
    {
        int number = nums[start][i];
        printf("%d ", number);
    }
    
    // 从上到下打一列
    if (start < row-start-1)
    {
        for (int i = start + 1; i < row-start; ++i)
        {
            int number = nums[i][start];
            printf("%d ", number);
        }
    }
    
    // 从右到左打一行
    if (start < col-start-1 && start < row-start-1)
    {
        for (int i = col-start-2; i >= start; --i)
        {
            int number = nums[row-start-1][i];
            printf("%d ", number);
        }
    }
    
    // 从下到上打一列
    if (start < col-start-1 && start < row-start-2)
    {
        for (int i = row-start-2; i >= start + 1; --i)
        {
            int number = nums[i][start];
            printf("%d ", number);
        }
    }
}

void PrintMatrixClock(int nums[][COL], int col, int row)
{
    if (nums==NULL || col<=0 || row<=0)
        return;
    int start = 0;
    
    while (col>start*2 && row>start*2)
    {
        PrintMatrixCircle(nums, col, row, start);
        ++start;
    }
}

int main()
{
    int nums[ROW][COL] = {{1,2,3,4},{5,6,7,8},{9,10,11,12},{13,14,15,16}};
    
    PrintMatrixClock(nums, COL, ROW);
    
    return 0;
}