剑指offer系列13：顺时针打印矩阵

这种题，必然要一圈一圈循环，因此，考虑两个问题：1.如何终止循环 2.如何打印一圈

我今天偷懒了， main函数是我从答案搬来的。

#include<iostream>
#include<vector>
using namespace std;
class Solution {
public:
    vector<int> printMatrix(vector<vector<int> > matrix) {
        int row = matrix.size();
        int col = matrix[0].size();
        int left = 0, right = col-1;//列标
        int top = 0, bot = row-1;//行标
        vector<int>  result;
        while (left <=right&&top <= bot)
        {
            //打印上面一行，列是变量
            for (int i = left; i <= right; i++)
            {
                result.push_back(matrix[top][i]);
            }
            //打印右边一列,行是变量
            if (bot > top)
            {
                for (int i = top+1; i <=bot; i++)
                {
                    result.push_back(matrix[i][right]);
                }
            }
            //打印下边一行，列是变量
            if (bot > top&&right > left)
            {
                for (int i = right-1; i >=left; i--)
                {
                    result.push_back(matrix[bot][i]);
                    
                }
            }
            //打印左边一列，行是变量
            if (bot-top>1  && right > left)
            {
                for (int i = bot-1; i >top; i--)
                {
                    result.push_back(matrix[i][left]);                
                }
            }
            top++;
            right--;
            bot--;
            left++;

        }
        return result;
    }
};
int main()
{
    int a1[] = { 1,  2,  3,  4 };
    int a2[] = { 5,  6,  7,  8 };
    int a3[] = { 9, 10, 11, 12 };
    int a4[] = { 13, 14, 15, 16 };
    //    int a1[] = { 1 };
    //    int a2[] = { 2 };
    //    int a3[] = { 3 };
    //    int a4[] = { 4 };

    vector<int> vec1(a1, a1 + 4);
    vector<int> vec2(a2, a2 + 4);
    vector<int> vec3(a3, a3 + 4);
    vector<int> vec4(a4, a4 + 4);


    vector< vector<int> > vec;
    vec.push_back(vec1);
    vec.push_back(vec2);
    vec.push_back(vec3);
    vec.push_back(vec4);

    Solution solu;
    vector<int> res = solu.printMatrix(vec);
    for (int i = 0; i < res.size(); i++)
    {
        cout << res[i] << " ";
    }
    return 0;
}