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workspace/c/luogu/p1141.cpp
e2hang ebcee63b7c New
2026-01-09 00:05:37 +08:00

63 lines
1.5 KiB
C++

#include <iostream>
#include <vector>
using namespace std;
int dx[] = {1, 0, -1, 0}; //r u l d
int dy[] = {0, -1, 0, 1}; //r u l d (u, d)
// ^ ^
vector<vector<int>> mp;
vector<int> parent;
vector<bool> visited;
int ans = 0;
int find(int x){
if(x != parent[x]) parent[x] = find(parent[x]);
return parent[x];
}
void merge(int x, int y){
int xa = find(x);
int ya = find(y);
if(xa != ya) parent[xa] = ya;
}
void dfs(int x, int y, int n, int num){
if(x < 0 || y < 0 || x >= n || y >= n) return;
visited[x * n + y] = true;
for(int i = 0; i < 4; i++){
int nx = x + dx[i];
int ny = y + dy[i];
if(nx >= 0 && ny >= 0 && ny < n && nx < n){
int numt = mp[nx][ny];
if(!visited[nx * n + y] && num != numt){
merge(nx * n + ny, x * n + y);
dfs(nx, ny, n, numt);
}
}
}
}
int main(){
int n, m;
cin >> n >> m;
mp.resize(n, vector<int>(n));
parent.resize(n * n);
visited.resize(n * n, false);
for(int i = 0; i < n; ++i){
for(int j = 0; j < n; ++j){
cin >> mp[i][j];
}
}
int a, b;
for(int i = 0; i < m; ++i){
cin >> a >> b;
a--; b--;
//一次
ans = 0;
/*for(int i = 0; i < n * n; ++i){
parent[i] = i;
}*/
visited.resize(n * n, false);
dfs(a, b, n, mp[a][b]);
cout << ans << endl;
}
return 0;
}