[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.

class Solution {public:    vector<int> printMatrix(vector<vector<int> > matrix) {        vector<int> v;        if(matrix.empty()||matrix[0].empty())            return v;        int rows = matrix.size();        int cols = matrix[0].size();        int left = 0, top = 0, right = cols - 1, bottom = rows - 1;        while(left<=right && top <= bottom)        {            for(int i=left;i<=right;++i)                v.push_back(matrix[top][i]);            for(int j=top+1;j<=bottom;++j)                v.push_back(matrix[j][right]);            if (top != bottom)                for(int i=right-1;i>=left;--i)                    v.push_back(matrix[bottom][i]);            if (left != right)                for(int j=bottom-1;j>top;--j)                    v.push_back(matrix[j][left]);            left++,top++,right--,bottom--;        }        return v;    }};