week8

第一题 P1616 疯狂的采药

没开longlong!!!基本就是跟着学长写的。。。

#include<bits/stdc++.h>
using namespace std;
const int maxn = 1e7+10;
const int maxn1 = 1e4 + 10;
int w[maxn1];
int v[maxn1];
long long dp[2][maxn];
int main() {
	int m;
	int w0;
	//w0背包大小
	cin >> w0 >> m;
	for (int i = 1; i <= m; i++) {
		cin >> w[i] >> v[i];
		
	}

	int now=0,pre=0;
	memset(dp[0], 0, sizeof(dp[0]));
	for (int i = 1; i <= m; i++) {
		
		now = i & 1;
		pre = (i - 1) & 1;
		dp[now][0] = 0;
		for (int j = 1; j <= w0;j++) {
			
			if (w[i] > j) {
				dp[now][j] = dp[pre][j];
			}
			else {
				dp[now][j] = max(dp[pre][j], dp[now][j - w[i]] + v[i]);
			}
		}
	}
	cout << dp[m & 1][w0];
}

第二题 P1833 樱花

普普通通的多重背包个屁，这是01和多重混在一起了，于是就塞了个判断进去，判断走那种方法，

#include<bits/stdc++.h>
using namespace std;
int n;
int dp[10010][1010];
const int maxn = 10000 + 100;
int w[maxn];
int v[maxn];
int c[maxn];
int main() {
	int time1, time2, time3, time4, time;
	char time5;
	cin >> time1 >> time5 >> time2 >> time3 >> time5 >> time4;
	time = (time3 - time1 - 1) * 60 + 60 - time2 + time4;
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> w[i] >> v[i] >> c[i];

	}
	memset(dp[0], 0, sizeof(dp[0]));
	for (int i = 1; i <= n; i++) {
		int now = i & 1;
		int pre = (i - 1) & 1;
		for (int j = 0; j <= time; j++) {
			if (c[i] == 0) {
				if (w[i] <= j) {
					dp[now][j] = max(dp[pre][j], dp[now][j - w[i]] + v[i]);
				}
				else {
					dp[now][j] = dp[pre][j];
				}
			}
			if (c[i] == 1)
				if (w[i] <= j) {
					dp[now][j] = max(dp[pre][j], dp[pre][j - w[i]] + v[i]);
				}
				else {
					dp[now][j] = dp[pre][j];
				}
			if (c[i] > 1) {
				for (int k = 0; k <= c[i] && w[i] * k <= j; k++) {
					dp[now][j] = max(dp[pre][j], dp[pre][j - k * w[i]] + v[i] * k);
				}
			}
		}
	}
	cout << dp[n&1][time];
}

第三题 P1077 [NOIP2012 普及组] 摆花

方程：dp[i][j] = dp[i][j] + dp[i - 1][j - k]，稳得一批；
i是当前讨论的花，k是这种花放几朵
则转k次循环，和j相等就停止
dp=当前情况已知的种数+不放该花并且空出k个空的种数。

#include<bits/stdc++.h>
using namespace std;
const int maxn = 100+5, b = 1000007;
int n, m, a[maxn], dp[maxn][maxn];
int main()
{
    cin >> n >> m;
    for (int i = 1; i <= n; i++) cin >> a[i];
    dp[0][0] = 1;
    for (int i = 1; i <= n; i++)
        for (int j = 0; j <= m; j++)
            for (int k = 0; k <= min(j, a[i]); k++)
                dp[i][j] = (dp[i][j] + dp[i - 1][j - k]) % b;
    cout << dp[n][m] << endl;
    return 0;
}

第四题

写了个分组背包，应该，算吧。。。。

#include<bits/stdc++.h>
using namespace std;
struct wu
{
    int v;
    int w;
};
struct node2
{
    int v, p, q, num;
}y[65];
vector<wu>h[100];
int dp[34010];
bool cmp(node2 a, node2 b)
{
    return a.q < b.q;
}
int main()
{
    int n, m, i, j, k;
    int cnt = 0;
    cin >> n >> m;
    for (i = 1; i <= m; i++)
    {
        cin>>y[i].v>>y[i].p>>y[i].q;
        y[i].num = i;
    }
    sort(y + 1, y + m + 1, cmp);
    for (i = 1; i <= m; i++)
    {
        wu x;
        if (y[i].q == 0)
        {
            x.v = y[i].v;
            x.w = y[i].v * y[i].p;
            h[y[i].num].push_back(x);
        }
        else
        {
            int s = h[y[i].q].size();
            for (j = 0; j < s; j++)
            {
                x.v = y[i].v + h[y[i].q][j].v;
                x.w = y[i].v * y[i].p + h[y[i].q][j].w;
                h[y[i].q].push_back(x);
            }
        }
    }
    for (i = 1; i <= m; i++)
    {
        if (h[i].size() == 0) {
            continue;
        }
        for (j = n; j >= 0; j--)
        {
            for (k = 0; k < h[i].size(); k++)
            {
                if (h[i][k].v <= j) dp[j] = max(dp[j], dp[j - h[i][k].v] + h[i][k].w);
            }
        }
    }
    cout << dp[n];
    return 0;
}