44 lines
1.0 KiB
C++
44 lines
1.0 KiB
C++
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/**
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* File: climbing_stairs_backtrack.cpp
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* Created Time: 2023-06-30
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* Author: krahets (krahets@163.com)
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*/
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#include "../utils/common.hpp"
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/* <20><><EFBFBD><EFBFBD> */
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void backtrack(vector<int> &choices, int state, int n, vector<int> &res) {
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// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> n <20><>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 1
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if (state == n)
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res[0]++;
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// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѡ<EFBFBD><D1A1>
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for (auto &choice : choices) {
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// <20><>֦<EFBFBD><D6A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Խ<EFBFBD><D4BD><EFBFBD><EFBFBD> n <20><>
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if (state + choice > n)
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continue;
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// <20><><EFBFBD>ԣ<EFBFBD><D4A3><EFBFBD><EFBFBD><EFBFBD>ѡ<EFBFBD><EFBFBD><F1A3ACB8><EFBFBD>״̬
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backtrack(choices, state + choice, n, res);
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// <20><><EFBFBD><EFBFBD>
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}
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}
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/* <20><>¥<EFBFBD>ݣ<EFBFBD><DDA3><EFBFBD><EFBFBD><EFBFBD> */
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int climbingStairsBacktrack(int n) {
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vector<int> choices = {1, 2}; // <20><>ѡ<EFBFBD><D1A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 1 <20><EFBFBD> 2 <20><>
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int state = 0; // <20>ӵ<EFBFBD> 0 <20><EFBFBD>ʼ<EFBFBD><CABC>
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vector<int> res = {0}; // ʹ<><CAB9> res[0] <20><>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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backtrack(choices, state, n, res);
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return res[0];
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}
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/* Driver Code */
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int main() {
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int n = 9;
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int res = climbingStairsBacktrack(n);
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cout << "<EFBFBD><EFBFBD> " << n << " <20><>¥<EFBFBD>ݹ<EFBFBD><DDB9><EFBFBD> " << res << " <20>ַ<EFBFBD><D6B7><EFBFBD>" << endl;
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return 0;
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}
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