시간 제한 | 메모리 제한 | 제출 | 정답 | 맞힌 사람 | 정답 비율 |
---|---|---|---|---|---|
8 초 (추가 시간 없음) | 512 MB | 5 | 5 | 4 | 100.000% |
There is a grid of size W × H surrounded by walls. Some cells in the grid are occupied by slimes. The slimes want to unite with each other and become a “King Slime”.
In each move, a slime can move to east, west, south and north direction until it enters a cell occupied by another slime or hit the surrounding wall. If two slimes come together, they unite and become a new slime.
Your task is write a program which calculates the minimum number of moves that all the slimes unite and become a King Slime. Suppose slimes move one by one and they never move simultaneously
The first line contains three integers N (2 ≤ N ≤ 40, 000), W and H (1 ≤ W, H ≤ 100, 000), which denote the number of slimes, the width and the height of the grid respectively.
The following N lines describe the initial coordinates of the slimes. The i-th line contains two integers xi (1 ≤ xi ≤ W) and yi (1 ≤ yi ≤ H), which indicate the coordinates of the i-th slime . All the coordinates are 1-based.
You may assume that each cell is occupied by at most one slime initially.
Output the minimum number of moves that all the slimes unite and become a King Slime.
4 3 3 1 1 1 3 3 1 3 3
3
2 3 3 2 2 3 3
2
2 4 4 2 2 3 3
3
2 4 4 2 2 2 3
1