牛客网——剑指offer 顺时针打印矩阵

题目描述

输入一个矩阵，按照从外向里以顺时针的顺序依次打印出每一个数字，例如，如果输入如下4 X 4矩阵： 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 则依次打印出数字1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10.

vector<int> printMatrix(vector<vector<int> > matrix) {
        int len = (matrix.size())*(matrix[0].size()),flag = 0;
        
        int left,right,up,down;
        left = 0,right = matrix[0].size()-1;
        up = 0,down = matrix.size()-1;
        
        int x = 0, y = -1;
        
        vector<int> temp;
//        if(len == 0) return temp;
//        if(len == 1){temp.push_back(matrix[0][0]);return temp;}
        
        while(flag < len)
        {
            while(flag<len && y<right) {temp.push_back(matrix[x][++y]);flag++;}
            while(flag<len && x<down)  {temp.push_back(matrix[++x][y]);flag++;}
            while(flag<len && y>left)  {temp.push_back(matrix[x][--y]);flag++;}
            while(flag<len && x>up+1)  {temp.push_back(matrix[--x][y]);flag++;}
            
            right--,down--,left++,up++;
        }
        
        return temp;
    }