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35 lines
732 B
35 lines
732 B
#include <bits/stdc++.h>
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using namespace std;
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const int N = 20;
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// 学习视频
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// https://www.bilibili.com/video/BV1nE411A7ST
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int g[N];
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// f(0)*f(n-1)+f(1)*f(n-2)+....+f(n-1)*f(0)
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// 递归
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int f(int n) {
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if (n <= 1) return 1;
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int sum = 0;
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for (int i = 0; i < n; i++)
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sum += f(i) * f(n - 1 - i);
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return sum;
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}
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int main() {
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// 1、递推法
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g[0] = g[1] = 1;
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for (int i = 2; i < N; i++)
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for (int j = 0; j < i; j++)
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g[i] += g[j] * g[i - 1 - j]; // 考虑思路：画括号法
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for (int i = 0; i < N; i++)
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cout << g[i] << endl;
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// 2 、递归法
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for (int i = 0; i < N; i++)
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cout << f(i) << endl;
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return 0;
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} |