43 lines
799 B
C++
43 lines
799 B
C++
|
#include <bits/stdc++.h>
|
||
|
|
|
||
|
|
using namespace std;
|
||
|
|
|
||
|
|
struct Node {
|
||
|
|
int num;
|
||
|
|
int step;
|
||
|
|
};
|
||
|
|
|
||
|
|
const int N = 1010;
|
||
|
|
int n, m;
|
||
|
|
queue<Node> q;
|
||
|
|
int st[N];
|
||
|
|
|
||
|
|
void bfs() {
|
||
|
|
q.push({n, 0});
|
||
|
|
while (q.size()) {
|
||
|
|
auto x = q.front();
|
||
|
|
q.pop();
|
||
|
|
if (x.num == m) {
|
||
|
|
printf("%d\n", x.step);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
if (!st[x.num + 1]) {
|
||
|
|
q.push({x.num + 1, x.step + 1});
|
||
|
|
st[x.num + 1] = 1;
|
||
|
|
}
|
||
|
|
if (!st[x.num - 1]) {
|
||
|
|
q.push({x.num - 1, x.step + 1});
|
||
|
|
st[x.num - 1] = 1;
|
||
|
|
}
|
||
|
|
if (!st[x.num * 2]) {
|
||
|
|
q.push({x.num * 2, x.step + 1});
|
||
|
|
st[x.num * 2] = 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
int main() {
|
||
|
|
cin >> n >> m;
|
||
|
|
bfs();
|
||
|
|
return 0;
|
||
|
|
}
|