30 lines
656 B
C++
30 lines
656 B
C++
#include <bits/stdc++.h>
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using namespace std;
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int a, b;
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const int N = 10010;
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bool st[N];
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typedef pair<int, int> PII;
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void bfs() {
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queue<PII> q; // q.first 当前是哪个数 q.second 从出发点到q.first走了几步
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q.push({a, 0});
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st[a] = true;
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while (q.size()) {
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auto t = q.front();
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q.pop();
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int u = t.first;
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int d = t.second;
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if (u == b) {
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cout << d << endl;
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exit(0);
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}
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if (!st[u + 1]) q.push({u + 1, d + 1});
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if (!st[u * 2]) q.push({u * 2, d + 1});
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}
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}
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int main() {
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cin >> a >> b;
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bfs();
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return 0;
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} |