40 lines
848 B
C++
40 lines
848 B
C++
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/**
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* File: climbing_stairs_dfs_mem.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>仯<EFBFBD><E4BBAF><EFBFBD><EFBFBD> */
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int dfs(int i, vector<int> &mem) {
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// <20><>֪ dp[1] <20><> dp[2] <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮
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if (i == 1 || i == 2)
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return i;
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// <20><><EFBFBD><EFBFBD><EFBFBD>ڼ<EFBFBD>¼ dp[i] <20><><EFBFBD><EFBFBD>ֱ<EFBFBD>ӷ<EFBFBD><D3B7><EFBFBD>֮
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if (mem[i] != -1)
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return mem[i];
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// dp[i] = dp[i-1] + dp[i-2]
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int count = dfs(i - 1, mem) + dfs(i - 2, mem);
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// <20><>¼ dp[i]
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mem[i] = count;
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return count;
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}
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/* <20><>¥<EFBFBD>ݣ<EFBFBD><DDA3><EFBFBD><EFBFBD>仯<EFBFBD><E4BBAF><EFBFBD><EFBFBD> */
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int climbingStairsDFSMem(int n) {
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// mem[i] <20><>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD> i <20>ķ<D7B5><C4B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-1 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼
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vector<int> mem(n + 1, -1);
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return dfs(n, mem);
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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 = climbingStairsDFSMem(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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