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26 lines
749 B
26 lines
749 B
#include <bits/stdc++.h>
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using namespace std;
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//完全背包的原始未优化版本
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const int N = 1010;
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int f[N][N];
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int v[N], w[N];
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int main() {
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int n, m;
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scanf("%d %d", &n, &m);
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for (int i = 1; i <= n; i++) scanf("%d %d", &v[i], &w[i]);
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//多层循环,万恶之源
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//优化的策略是想办法干掉最里层的循环,就是经典的类比法对比公式,
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//f[i][j-v] 去类比,用一个式子代替掉一层循环,使得时间复杂度降低
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for (int i = 1; i <= n; i++)
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for (int j = 0; j <= m; j++)
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for (int k = 0; k * v[i] <= j; k++)
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f[i][j] = max(f[i][j], f[i - 1][j - k * v[i]] + k * w[i]);
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printf("%d\n", f[n][m]);
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return 0;
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}
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