Problem
You are given four integers sx, sy, fx, fy, and a non-negative integer t.
In an infinite 2D grid, you start at the cell (sx, sy). Each second, you must move to any of its adjacent cells.
Return true **if you can reach cell *(fx, fy) after exactly** t **seconds***, *or* false **otherwise**.
A cell's adjacent cells are the 8 cells around it that share at least one corner with it. You can visit the same cell several times.
Example 1:
Input: sx = 2, sy = 4, fx = 7, fy = 7, t = 6
Output: true
Explanation: Starting at cell (2, 4), we can reach cell (7, 7) in exactly 6 seconds by going through the cells depicted in the picture above.
Example 2:
Input: sx = 3, sy = 1, fx = 7, fy = 3, t = 3
Output: false
Explanation: Starting at cell (3, 1), it takes at least 4 seconds to reach cell (7, 3) by going through the cells depicted in the picture above. Hence, we cannot reach cell (7, 3) at the third second.
Constraints:
1 <= sx, sy, fx, fy <= 1090 <= t <= 109
Solution (Java)
class Solution {
boolean isReachableAtTime(int sx, int sy, int fx, int fy, int t) {
int xdiff = Math.abs(sx - fx), ydiff = Math.abs(sy - fy);
if(xdiff == 0 && ydiff == 0 && t == 1) return false;
return (Math.min(xdiff, ydiff) + Math.abs(xdiff - ydiff)) <= t;
}
}
Explain:
nope.
Complexity:
- Time complexity : O(n).
- Space complexity : O(n).