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https://git.sb/baoshuo/OI-codes.git
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52 lines
908 B
C++
52 lines
908 B
C++
#include <iostream>
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#include <vector>
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using std::cin;
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using std::cout;
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const char endl = '\n';
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const int N = 105;
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int m, n, w[N], f[N][N];
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std::vector<int> g[N];
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void dfs(int u) {
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// 一门课也不选学分显然为 0
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f[u][0] = 0;
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for (int v : g[u]) {
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dfs(v);
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for (int i = n; ~i; i--) { // 选课总数
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for (int j = i; ~j; j--) { // 子树内选课总数
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f[u][i] = std::max(f[u][i], f[u][i - j] + f[v][j]);
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}
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}
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}
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if (u) {
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for (int i = n; i; i--) {
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f[u][i] = f[u][i - 1] + w[u]; // 选这门课也应获得相应学分
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}
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}
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}
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int main() {
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std::ios::sync_with_stdio(false);
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cin.tie(nullptr);
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cin >> m >> n;
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for (int i = 1, x; i <= m; i++) {
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cin >> x >> w[i];
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g[x].push_back(i);
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}
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dfs(0);
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cout << f[0][n] << endl;
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return 0;
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}
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