动态规划DP题目汇总+代码总结(三)
作者:
就是要AC
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2021-05-16 20:58:55
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所有人可见
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阅读 404
AcWing 187. 导弹防御系统
#include <iostream>
#include <algorithm>
using namespace std;
const int N = 55;
int n;
int q[N];
int up[N], down[N];
int ans;
void dfs(int u, int su, int sd)
{
if (su + sd >= ans) return;
if (u == n)
{
ans = su + sd;
return;
}
int k = 0;
while (k < su && up[k] >= q[u]) k++;
int t = up[k];
up[k] = q[u];
if (k < su) dfs(u + 1, su, sd);
else dfs(u + 1, su + 1, sd);
up[k] = t;
k = 0;
while (k < sd && down[k] <= q[u]) k++;
t = down[k];
down[k] = q[u];
if (k < sd) dfs(u + 1, su, sd);
else dfs(u + 1, su, sd + 1);
down[k] = t;
}
int main()
{
while (cin >> n, n)
{
for (int i = 0; i < n; i++) cin >> q[i];
ans = n;
dfs(0, 0, 0);
cout << ans << endl;
}
return 0;
}
AcWing 902. 最短编辑距离
AcWing 899. 编辑距离
AcWing 1017. 怪盗基德的滑翔翼
AcWing 1014. 登山
AcWing 482. 合唱队形
背包模型
AcWing 2. 01背包问题
#include <iostream>
#include <algorithm>
using namespace std;
const int N = 1010;
int n, m;
int v[N], w[N];
int f[N][N];
int main()
{
cin >> n >> m;
for (int i = 1; i <= n; i++) cin >> v[i] >> w[i];
for (int i = 1; i <= n; i++)
for (int j = 0; j <= m; j++)
{
f[i][j] = f[i - 1][j];
if (j >= v[i]) f[i][j] = max(f[i][j], f[i - 1][j - v[i]] + w[i]);
}
cout << f[n][m] << endl;
return 0;
}
二维优化到一维
#include <iostream>
#include <algorithm>
using namespace std;
const int N = 1010;
int n, m;
int v[N], w[N];
int f[N];
int main()
{
cin >> n >> m;
for (int i = 1; i <= n; i++) cin >> v[i] >> w[i];
for (int i = 1; i <= n; i++)
for (int j = m; j >= v[i]; j--)
{
f[j] = max(f[j], f[j - v[i]] + w[i]);
}
cout << f[m] << endl;
return 0;
}