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| #include <bits/stdc++.h>
using namespace std;
pair<int,int> at(string s) {
return {'8' - s[1], s[0] - 'a'};
}
int knight(std::string start, std::string finish) {
if(start == finish) return 0;
queue<pair<int,int>> q;
vector<vector<int>> vis(8,vector<int>(8,INT_MAX));
auto push = [&](int y, int x, int c) {
if(vis[y][x] > c) {
vis[y][x] = c;
q.push({y,x});
}
};
push(at(start).first, at(start).second, 0);
int dy[8]{-1,-2,-2,-1,1,2,2,1}, dx[8]{-2,-1,1,2,2,1,-1,-2};
while(q.size()) {
auto [y,x] = q.front(); q.pop();
for(int i = 0; i < 8; i++) {
int ny = y + dy[i], nx = x + dx[i];
if(0 <= ny and ny < 8 and 0 <= nx and nx < 8) {
push(ny,nx,vis[y][x] + 1);
auto [gy,gx] = at(finish);
if(gy == ny and gx == nx) return vis[ny][nx];
}
}
}
return -1;
}
|
