基础背包dp题单

学习

算法学习——dd大佬:背包九讲(洛谷)

算法学习——dd大佬:背包九讲(博客园)

题单传送门

P236 采药

#include <bits/stdc++.h>
using namespace std;
int t, m;
int f[1005];
int main() {
	cin >> t >> m;
	for (int i = 1; i <= m; i++) {
		int v, w;
		cin >> v >> w;
		for (int j = t; j >= v; j--)
			f[j] = max(f[j], f[j - v] + w);
	}
	printf("%d\n", f[t]);
	return 0;
}

P237 开心的金明

#include <bits/stdc++.h>
using namespace std;
int mon, num, pr[30], mp[30], dp[30005];
int main() {
	cin >> mon >> num;
	for (int i = 1; i <= num; i++)
		cin >> pr[i] >> mp[i];//pr单价,mp单件物品的重要性
	for (int i = 1; i <= num; i++)
		for (int j = mon; j >= pr[i]; j--)
			dp[j] = max(dp[j], dp[j - pr[i]] + pr[i] * mp[i]);
	cout << dp[mon];
	return 0;
}
//dp[i][j]=max(dp[i][j],dp[i-1][j-pr[i]]+pr[i]*mp[i])

P238 完全背包问题

#include <iostream>
#define ll long long
using namespace std;
ll a[10005], b[10005], c[10005][10005];
int main() {
	int n, m;
	cin >> m >> n;
	for (int i = 1; i <= n; i++)
		cin >> a[i] >> b[i];
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			if (j < a[i])
				c[i][j] = c[i - 1][j];
			else
				c[i][j] = max(c[i - 1][j], c[i][j - a[i]] + b[i]);
		}
	}
	cout << "max=" << c[n][m];
	return 0;
}

P239 竞赛总分

#include <bits/stdc++.h>
using namespace std;
int m, n, i, j;
int s, t, f[10005];
int main() {
	cin >> m >> n;
	f[0] = 0;
	for (i = 1; i <= n; i++) {
		cin >> s >> t;
		for (j = t; j <= m; j++)
			if (f[j - t] + s > f[j])
				f[j] = f[j - t] + s;
	}
	cout << f[m];
	return 0;
}

P240 砝码称重

#include <bits/stdc++.h>
using namespace std;
int num[10];
int val[10] = {1, 2, 3, 5, 10, 20}, f[2005] = {0};
int value[2005];
int m, k, ans;
int main() {
	for (int i = 0; i < 6; i++) {
		cin >> num[i];
		m += val[i] * num[i];
	}
	for (int i = 0; i < 6; i++) {
		for (int j = 1; j <= num[i]; j *= 2) {
			value[k] = val[i] * j;
			num[i] -= j;
			k++;
		}
		if (num[i] != 0) {
			value[k] = val[i] * num[i];
			k++;
		}
	}
	for (int i = 0; i < k; i++)
		for (int j = m; j >= 1; j--)
			if (j >= value[i])
				f[j] = max(f[j], f[j - value[i]] + value[i]);
	for (int i = 1; i <= m; i++)
		if (f[i] == i)
			ans++;
	cout << "Total=" << ans << endl;
	return 0;
}

P241 最小乘车费用

#include <bits/stdc++.h>
using namespace std;
int dp[1005];
int n;
int main() {
	memset(dp, 0x3f3f3f3f, sizeof dp);
	for (int i = 1; i <= 10; i++)
		cin >> dp[i];
	cin >> n;
	for (int i = 2; i <= n; i++)
		for (int j = 1; j < i; j++)
			dp[i] = min(dp[i], dp[j] + dp[i - j]);
	cout << dp[n];
	return 0;
}

P242 逃亡的准备

#include<bits/stdc++.h>
using namespace std;
int n,m,v,w,p;
int val[10005];
int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>v>>w>>p;
		if(p==0||m/v<=p){
			for(int j=v;j<=m;j++)
				val[j]=max(val[j],val[j-v]+w);
		}
		else{
			int base=1;
			while(p){
				p-=base;
				int tv=base*v,tw=base*w;
				for(int j=m;j>=tv;j--)
					val[j]=max(val[j],val[j-tv]+tw);
				base*=2;
				base=min(base,p);
			}
		}
	}
	cout<<val[m];
	return 0;
}
//谢谢G,复习了二进制优化

P243 庆功会

#include<bits/stdc++.h>
using namespace std;
int n, m;
int v[100005], w[100005], s[100005];
int val[100005];
int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++)
		cin>>v[i]>>w[i]>>s[i];
	for(int i=1;i<=n;i++){
		for(int j=m;j>=v[i];j--){
			for(int k=1;k<=s[i];k++){
				if(k*v[i]>j) break;
				val[j]=max(val[j],val[j-v[i]*k]+w[i]*k);
			}
		}
	}
	cout<<val[m];
	return 0;
} 
//dp方程:val[j]=max(val[j],val[j-v[i]*k]+w[i]*j)
//val[j]表示价值
//如果不购买,val[j]=val[j]
//如果购买k个,val[j]=val[j-v[i]*k+w[i]*k

P244 混合背包

#include <bits/stdc++.h>
using namespace std;
int m, n;
int w[35], c[35], p[35];
int f[205];
int main() {
	cin >> m >> n;
	for (int i = 1; i <= n; i++)
		cin >> w[i] >> c[i] >> p[i];
	for (int i = 1; i <= n; i++)
		if (p[i] == 0) {
			for (int j = w[i]; j <= m; j++)
				f[j] = max(f[j], f[j - w[i]] + c[i]);
		} else {
			for (int j = 1; j <= p[i]; j++)
				for (int k = m; k >= w[i]; k--)
					f[k] = max(f[k], f[k - w[i]] + c[i]);
		}
	cout << f[m];
	return 0;
}

P245 NASA的食物计划

#include <bits/stdc++.h>
using namespace std;
int f[405][405] = {0};
int v, m, n, x, y, z;
int main() {
	cin >> v >> m >> n;
	while (n--) {
		cin >> x >> y >> z;
		for (int i = v; i >= x; i--)
			for (int j = m; j >= y; j--)
				f[i][j] = max(f[i][j], f[i - x][j - y] + z);
	}
	cout << f[v][m];
}
//状态转移方程:f[k][i][j]=max{f[k-1][i][j],f[k-1][i-v[k]][j-m[k]]}

P246 分组背包

#include <bits/stdc++.h>
using namespace std;
int v, n, t; //v背包容量,n物品数量,t组数
int w[35], c[35]; //w[i]物品重量,c[i]物品价值
int bag[15][35], val[205]; //bag[i][j]:物品j在i组中,val[i]:物品价值
int main() {
	cin >> v >> n >> t;
	for (int i = 1; i <= n; i++) {
		int x;
		cin >> w[i] >> c[i] >> x;
		bag[x][++bag[x][0]] = i;
	}
	for (int i = 1; i <= t; i++) {
		for (int j = v; j >= 0; j--) {
			for (int k = 1; k <= bag[i][0]; k++) {
				if (j >= w[bag[i][k]]) {
					if (val[j] < val[j - w[bag[i][k]]] + c[bag[i][k]]) {
						val[j] = val[j - w[bag[i][k]]] + c[bag[i][k]];
					}
				}
			}
		}
	}
	cout << val[v];
	return 0;
}
//dp方程:val[j]=max(val[j],val[j-w[bag[i][k]]]+c[bag[i][k]])

P247 新年趣事之打牌

#include <bits/stdc++.h>
using namespace std;
int N, sum, V, cnt;
int w[105], vis[100005], g[100005], ans[105];
int main() {
	cin >> V >> N;
	for (int i = 1; i <= N; i++) {
		cin >> w[i];
		sum += w[i];
	}
	V = sum - V;
	g[0] = 1;
	for (int i = 1; i <= N; i++) {
		for (int j = V; j >= w[i]; j--) {
			if (g[j - w[i]]) {
				if (!g[j]) vis[j] = i;
				g[j] += g[j - w[i]];
			}
		}
	}
	if (!g[V]) cout << "0";
	else if (g[V] >= 2) cout << "-1";
	else if (g[V] == 1) {
		for (int i = V; i >= 1; i -= w[vis[i]])
			ans[++cnt] = vis[i];
		sort(ans + 1, ans + 1 + cnt);
		for (int i = 1; i <= cnt; i++)
			cout << ans[i] << " ";
	}
	return 0;
}

P248 积木城堡

#include <bits/stdc++.h>
using namespace std;
int high[10005], v[10005], n, ni, sum, maxsum, a[10005];
int main() {
	cin >> n;
	for (int i = 1; i <= n; i++) {
		ni = 1;
		sum = 0;
		cin >> a[ni];
		sum += a[ni];
		while (a[ni] != -1) {
			ni++;
			scanf("%d", &a[ni]);
			sum += a[ni];
		}
		ni--;
		sum++;
		if (sum > maxsum)
			maxsum = sum;
		for (int j = 1; j <= sum; j++)
			v[j] = 0;
		v[0] = 1;
		for (int j = 1; j <= ni; j++)
			for (int k = sum; k >= a[j]; k--)
				if (!v[k] && v[k - a[j]]) {
					v[k] = 1;
					high[k]++;
				}
	}
	for (int i = maxsum; i >= 1; i--)
		if (high[i] == n) {
			printf("%d", i);
			return 0;
		}
	printf("0");
}
posted @ 2024-01-07 16:01  Foiled  阅读(7)  评论(0编辑  收藏  举报