1 /*
2 题目描述：
3 有一个NxN整数矩阵，请编写一个算法，将矩阵顺时针旋转90度。
4 给定一个NxN的矩阵，和矩阵的阶数N,请返回旋转后的NxN矩阵,保证N小于等于300。
5 测试样例：
6 [[1,2,3],[4,5,6],[7,8,9]],3
7 返回：[[7,4,1],[8,5,2],[9,6,3]]
8 */
9 /*
10 将矩阵顺时针旋转90度
11 一圈一圈的进行旋转(交换)。
12 eg:
13 1 2 3
14 4 5 6
15 7 8 9
16 先旋转外圈：
17 首先交换1->3->9->7->1;
18 然后交换2->6->8->4->2;
19 */
20 #include <iostream>
21 #include <vector>
22 using namespace std;
23
24 void rotateEdge(vector<vector<int> > &m, int tr, int tc, int dr, int dc){
25 int times = dc - tc;
26 int tmp = 0;
27 for (int i = 0; i < times; i++){
28 tmp = m[tr][tc+i];
29 m[tr][tc+i] = m[dr-i][tc];
30 m[dr-i][tc] = m[dr][dc-i];
31 m[dr][dc-i] = m[tr+i][dc];
32 m[tr+i][dc] = tmp;
33 }
34 }
35 vector<vector<int> > rotateMatrix(vector<vector<int> > mat, int n) {
36 // write code here
37 int tR = 0;
38 int tC = 0;
39 int dR = n-1;
40 int dC = n-1;
41 while (tR < dR){
42 rotateEdge(mat, tR++, tC++, dR--, dC--);
43 }
44 return mat;
45 }
46 int main(){
47 vector<vector<int> > matrix;
48 vector<int> a;
49 a.push_back(1);
50 a.push_back(2);
51 a.push_back(3);/*
52 a.push_back(4);*/
53 matrix.push_back(a);
54
55 vector<int> b;
56 b.push_back(4);
57 b.push_back(5);
58 b.push_back(6);/*
59 b.push_back(8);*/
60 matrix.push_back(b);
61
62 vector<int> c;
63 c.push_back(7);
64 c.push_back(8);
65 c.push_back(9);/*
66 c.push_back(12);*/
67 matrix.push_back(c);
68
69 vector<vector<int> > rt;
70 rt = rotateMatrix(matrix,3);
71 for (int i = 0; i < 3; i++){
72 for (int j = 0; j < 3; j++)
73 cout << rt[i][j] << ",";
74 cout << endl;
75 }
76 return 0;
77 }
