旋转矩阵

public static void Rotate(int[][] arr){
		int ar = 0;
		int ac = 0;
		int dr = arr.length-1;
		int dc = arr[0].length-1;
		while(ar<dr){
			rotateMatrix(arr,ar++,ac++,dr--,dc--);
		}
	}
	
	public static void rotateMatrix(int[][] arr,int ar,int ac,int dr,int dc){
		int temp = 0;
		int t = dr-ar;
		//四个点互换，
		for(int i=0;i<t;i++){
			temp = arr[ar][ac+i];
			arr[ar][ac+i] = arr[dr-i][ac];
			arr[dr-i][ac] = arr[dr][dc-i];
			arr[dr][dc-i] = arr[ar+i][dc];
			arr[ar+i][dc] = temp;
		}
	}

转圈打印矩阵

public static void circle(int[][] arr){
		int ar = 0;
		int ac = 0;
		int dr = arr.length-1;
		int dc = arr[0].length-1;
		while(ar<=dr&&ac<=dc){
			circlePrint(arr,ar++,ac++,dr--,dc--);
		}
	}
	
	public static void circlePrint(int[][] arr,int ar,int ac,int dr,int dc){
		if(ar==dr){
			for(int i=0;i<=dc;i++){
				System.out.print(arr[ar][i]+",");
			}
		}else if(ac==dc){
			for(int i=0;i<=dr;i++){
				System.out.print(arr[i][ac]+",");
			}
		}else{
			int t1 = ar;
			int t2 = ac;
			//打印第一行，从a(0,0)到a(0,dc-1)
			while(t2!=dc){
				System.out.print(arr[ar][t2++]+",");
			}
			//打印最后一列，从a(0,dc)到a(dr-1,dc)
			while(t1!=dr){
				System.out.print(arr[t1++][dc]+",");
			}
			//打印最后一行，从a(dr,dc-1)到a(dr,ac+1)
			while(dc!=ac){
				System.out.print(arr[dr][dc--]+",");
			}
			//打印第一列，从a(dr,ac)到a(ar+1,ac)
			while(dr!=ar){
				System.out.print(arr[dr--][ac]+",");
			}
			
		}
	}