洛谷P1455搭配购买

传送门啦

这是强连通分量与背包的例题

需要注意的就是价值和价格两个数组不要打反了。。

另外 这是双向图！！！

#include <iostream>

#include <cstdio>

#include <cstring>

#include <algorithm>

using namespace std;

const int maxn = 1e4 + 4;

const int maxm = 5005;

int n,m,mon;

int c[maxn],w[maxn],u,v;

int C[maxn],W[maxn],f[maxn];

int head[maxn],tot;

int dfn[maxn],low[maxn],ind;

int num[maxn],belong[maxn],cnt,stack[maxn],top;

bool ins[maxn];

struct Edge{

	int to,next,from;

}edge[maxm << 1];

void add(int u,int v){

	edge[++tot].from = u;

	edge[tot].to = v;

	edge[tot].next = head[u];

	head[u] = tot;

}

int read(){

	char ch = getchar();

	int f = 1 , x = 0;

	while(ch > '9' || ch < '0'){

		if(ch == '-')  f = -1;

		ch = getchar();

	}

	while(ch >= '0' && ch <= '9'){

		x = x * 10 + ch - '0';

		ch = getchar();

	}

	return x * f;

}

void tarjan(int x){

	dfn[x] = low[x] = ++ind;

	stack[++top] = x;

	ins[x] = true;

	for(int i=head[x];i;i=edge[i].next){

		int v = edge[i].to;

		if(!dfn[v]){

			tarjan(v);

			low[x] = min(low[x] , low[v]);

		}

		else if(ins[v])  low[x] = min(low[x] , dfn[v]);

	}

	int k = 0;

	if(dfn[x] == low[x]){

		++cnt;

		do{

			k = stack[top];

			num[cnt]++;

			top--;

			ins[k] = false;

			belong[k] = cnt;

			C[cnt] += c[k];

			W[cnt] += w[k];

		} while(k != x);

	}

}

int main(){

	n = read();  m = read();  mon = read();

	for(int i=1;i<=n;i++){

		c[i] = read();  w[i] = read();

	}

	for(int i=1;i<=m;i++){

		u = read();  v = read();

		add(u,v);

		add(v,u);

	}

	for(int i=1;i<=n;i++)

	  if(!dfn[i])  tarjan(i);

	for(int i=1;i<=cnt;i++)

	  for(int j=mon;j>=C[i];j--)

	    f[j] = max(f[j] , f[j - C[i]] + W[i]);

	printf("%d",f[mon]);

	return 0;

}