LeetCode: Spiral Matrix II

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 ]]

class Solution {public:    vector<vector<int> > generateMatrix(int n) {        vector<int> temp(n, 0);        vector<vector<int> > result(n, temp);max = n * n;if(n == 0)return result;print(0, n, 0, n, 0, 1, result);return result;    }private:int max;    void print(int startX, int endX, int startY, int endY, int turn, int value, vector<vector<int> > &result)    {        int x, y;        if(startX >= endX || startY >= endY || value > max)            return;        turn = turn % 4;        if(turn == 0)        {            y = startY;            x = startX;            while(y < endY)            {                result[x][y] = value;                y++;                value++;            }            print(startX + 1, endX, startY, endY, turn + 1,value, result);        }        else if(turn == 1)        {            y = endY - 1;            x = startX;            while(x < endX)            {                result[x][y] = value;                x++;value++;            }            print(startX, endX, startY, endY - 1, turn + 1, value, result);                    }        else if(turn == 2)        {            y = endY - 1;            x = endX - 1;            while(y >= startY)            {                result[x][y] = value;                y--;value++;            }            print(startX, endX - 1, startY, endY, turn + 1, value, result);                    }        else        {            y = startY;            x = endX - 1;            while(x >= startX)            {                result[x][y] = value;                x--;value++;            }            print(startX, endX, startY + 1, endY, turn + 1, value, result);        }    }};

Round 2:

class Solution {public:    vector<vector<int> > generateMatrix(int n) {        int count = 1;        vector<int> temp(n, 0);        vector<vector<int> > result(n, temp);        int x = 0, y = 0, carry = 0;        while(count <= n*n)        {            while(x == carry && y < n-carry)            {                result[x][y] = count;                count++;                y++;            }            y--;            x++;            while(y == n-1-carry && x < n-carry)            {                result[x][y] = count;                count++;                x++;            }            x--;            y--;            while(x == n-1-carry && y >= carry)            {                result[x][y] = count;                count++;                y--;            }            y++;            x--;            while(y == carry && x > carry)            {                result[x][y] = count;                count++;                x--;            }            x++;            y++;            carry++;        }        return result;    }};