題目：輸入一個(gè)矩陣，按照從外向里以順時(shí)針的順序依次打印出每一個(gè)數(shù)字

• 思路 應(yīng)當(dāng)分為上下左右四步，并且設(shè)置一個(gè)boolean矩陣，來判斷是否能一直走。
  需要

public class printArray {
    public void printArrayOver(int[][] arr) {
        if(arr.length==0) return;
        int row = 0;
        int col = 0;
        boolean[][] visited = new boolean[arr.length+1][arr[0].length+1];
        for(int i=0;i<visited.length;i++){
            visited[i][0] = true;
            visited[i][visited.length-1]=true
        }
        for(int j=0;j<visited[0].length;j++){
            visited[0][j] = true;
            visited[visited.length-1][0]=true;
        }
        while(judge(arr,row,col)){
            if(judge(arr,startX,startY))
                right();
            if(judge(arr,startX,startY))
                down();
            if(judge(arr,startX,startY))
                left();
            if(judge(arr,startX,startY))
                up();
        }
    }
    public void left(){
        if(arr.length<=0) return;
        while(!visited[row+1][col+1]&&col<arr[0].length&&col>=0) {
            print(arr[row][col--]);
            visited[row+1][col+1] = true;
        }
    }
    public void right(){
        if(arr.length<=0) return;
        while(!visited[row+1][col+1]&&col<arr[0].length&&col>=0) {
            print(arr[row][col++]);
            visited[row+1][col+1] = true;
        }
    }
    public void down(){

        if(arr.length<=0) return;
        while(!visited[row+1][col+1]&&row<arr.length&&row>=0) {
            print(arr[row++][col]);
            visited[row+1][col+1] = true;
        }
    }
    public void up(){
        if(arr.length<=0) return;
        while(!visited[row+1][col+1]&&row<arr.length&&row>=0) {
            print(arr[row--][col]);
            visited[row+1][col+1] = true;
        }
    }
    public boolean judge(int[][] arr,int row,int col){
        boolean result = true;
        return visited[row-1][col]&&visited[row][col-1]&&visited[row+1][col]&&visited[row][col+1];
    }
}