59. 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 ]
]

public class Solution {
public int[][] generateMatrix(int n) {
int startx = 0,starty = 0,endx = n-1,endy = n-1;
int[][] ans = new int

;
int count = 1;
while(startx <= endx && starty <= endy){
for(int i = startx;i<=endx;i++){
ans[starty][i] = count++;
}
starty++;

for(int i = starty;i<=endy;i++){
ans[i][endx] = count++;
}
endx--;

for(int i = endx;i>=startx;i--){
ans[endy][i] = count++;
}
endy--;

for(int i = endy;i>=starty;i--){
ans[i][startx] = count++;
}
startx++;
}
return ans;
}
}