LEETCODE54/59 Spiral Matrix I/ii

One: Spiral Matrix I

Topic:

Given a matrix of m x n elements (m rows, n columns), return all elements of the Matri X in Spiral Order.

For example,
Given the following matrix:

[[1, 2, 3], [4, 5, 6], [7, 8, 9]]

You should return [1,2,3,6,9,8,7,4,5] .

Links: https://leetcode.com/problems/spiral-matrix/

Analysis: Look at the code, four while loops form a large circle

Class Solution {public:void DFS (int xi, int yi, const int &m, const int &n, vector<vector<int> > &        Amp;matrix, vector<int> &result, int **visited) {Visited[xi][yi] = 1;        Result.push_back (Matrix[xi][yi]);            while (Yi+1 < n &&!visited[xi][yi+1]) {//Four while loop just ran the Big Circle Result.push_back (Matrix[xi][yi+1]);            VISITED[XI][YI+1] = 1;        Yi = yi+1;            } while (Xi+1 < M &&!visited[xi+1][yi]) {result.push_back (Matrix[xi+1][yi]);            Visited[xi+1][yi] = 1;        Xi = XI +1;            } while (Yi-1 >=0 &&!visited[xi][yi-1]) {result.push_back (matrix[xi][yi-1]);            VISITED[XI][YI-1] = 1;        Yi = yi-1;            } while (Xi-1 >=0 &&!visited[xi-1][yi]) {result.push_back (Matrix[xi-1][yi]);            Visited[xi-1][yi] = 1;        Xi = xi-1; } if (Yi+1 < n &&!visited[xi][yi+1]) Dfs (xi, yi+1, M, N, Matrix, result, visited);        } vector<int> Spiralorder (vector<vector<int> > &matrix) {vector<int> result;        int m = Matrix.size ();                if (M = = 0) return result;        int n = matrix[0].size ();        int **visited= new INT*[M];            for (int i = 0; i < m; i++) {Visited[i] = new Int[n];        memset (Visited[i], 0, sizeof (int) *n);                } dfs (0, 0, m, N, Matrix, result, visited);        for (int i = 0; i < m; i++) Delete [] visited[i];        delete []visited;                    return result; }};

II: Spiral Matrix II

Topic:

Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.

For example,
Given N = 3 ,

You should return the following matrix:

[[1, 2, 3], [8, 9, 4], [7, 6, 5]]

Links: https://leetcode.com/problems/spiral-matrix-ii/

Class Solution {public:void DFS (int xi, int yi, const int &n, vector<vector<int> > &result, int &A         Mp;value) {Result[xi][yi] = value++;            while (Yi+1 < n &&!result[xi][yi+1]) {//Four while loop just ran the big circle result[xi][yi+1] = value++;        Yi = yi+1;            } while (Xi+1 < n &&!result[xi+1][yi]) {Result[xi+1][yi] = value++;        Xi = xi+1;            } while (yi-1 >= 0 &&!result[xi][yi-1]) {result[xi][yi-1] = value++;        Yi = yi-1;            } while (xi-1 >= 0 &&!result[xi-1][yi]) {Result[xi-1][yi] = value++;        Xi = xi-1;    } if (Yi+1 < n &&!result[xi][yi+1]) Dfs (xi, yi+1, n, result, value);        } vector<vector<int> > Generatematrix (int n) {vector<vector<int> >result;        if (n = = 0) return result; for (int i = 0; i < n; i++) {//Initialize result VECTor<int> temp (n, 0);        Result.push_back (temp);        } int value = 1;        DFS (0,0, n, result, value);            return result; }};

LEETCODE54/59 Spiral Matrix I/ii