/**
* 转圈打印一个二维数组(矩形)
*/
public class C05_RotateMatrix {
public static void printMatrix(int[][]arr){
if(arr==null || arr.length==0 || arr[0].length==0){
return ;
}
// (a,b) (c,d)
int a = 0;// 左上角,往数组右边走(行)
int b = 0;// 左上角,往数组下边走(列)
int c = arr[0].length - 1 ;// 右下角,往数组左边走(列)
int d = arr.length - 1;// 右下角,往数组上边走(行)
while(a<=c && b<=d){
printEdge(arr, a++, b++, c--, d--);//打印一圈
}
}
public static void printEdge(int[][] arr, int a, int b, int c, int d) {
if (a == c) {// 只有一列
for (int i = b; i <= d; i++) {
System.out.print(arr[i][a] + " ");
}
} else if (b == d) {// 只有一行
for (int i = a; i <= c; i++) {
System.out.print(arr[b][i] + " ");
}
} else {
int i = a;
while(i<c){
System.out.print(arr[b][i++]+" ");
}
i = b;
while(i<d){
System.out.print(arr[i++][c]+" ");
}
i = c;
while(i>a){
System.out.print(arr[d][i--]+" ");
}
i = d;
while(i>b){
System.out.print(arr[i--][a]+" ");
}
}
}
public static void main(String[] args) {
int arr[][] = new int[][]{
{1,2,3,4},
{5,6,7,8},
{9,10,11,12},
{13,14,15,16}
};
printMatrix(arr);
}
}
/*
{1,2,3,4}
{1,2,3,4},
{5,6,7,8},
{9,10,11,12},
{13,14,15,16}
{1,2,3,4},
{5,6,7,8},
{9,10,11,12},
{1,2,3},
{5,6,7},
{9,10,11},
{13,14,15}
*/