标签：customer any another bec return line bfs written numbers
3 3 3 1 10 2 1 2 2 2 1 3 3 1 2 6Sample Output
7
题意 ： 有N个顾客，有M个猪圈，每个猪圈有一定的猪，在开始的时候猪圈都是关闭的，
顾客来买猪，顾客打开某个猪圈，可以在其中挑选一定的猪的数量，在这个顾客走后，可以在打开的
猪圈中将某个猪圈的一些猪牵到另外一个打开的猪圈，然后所有的猪圈会关闭，这样下一个顾客来了继续上面的工作
思路分析 ：
参考此文章即可 ：http://wenku.baidu.com/view/0ad00abec77da26925c5b01c.html
代码示例 ：
const int maxn = 1e4+5;
const int inf = 0x3f3f3f3f;
int m, n;
int a[1005];
vector<int>ve[1005];
struct node
{
int to, flow;
int next;
}e[maxn];
int head[maxn];
int cnt = 0;
int s, t;
void addedge(int u, int v, int w){
e[cnt].next = head[u], e[cnt].to = v, e[cnt].flow = w, head[u] = cnt++;
e[cnt].next = head[v], e[cnt].to = u, e[cnt].flow = 0, head[v] = cnt++;
}
int belong[1005];
int dep[1005], que[maxn];
bool bfs(int s, int t){
int head1 = 0, tail = 1;
memset(dep, 0, sizeof(dep));
que[0] = s; dep[s] = 1;
while(head1 < tail){
int v = que[head1++];
for(int i = head[v]; i != -1; i = e[i].next){
int to = e[i].to;
if (e[i].flow && !dep[to]) {
dep[to] = dep[v]+1;
que[tail++] = to;
}
}
}
return dep[t];
}
int dfs(int u, int f1){
if (f1 == 0 || u == t) return f1;
int f = 0;
for(int i = head[u]; i != -1; i = e[i].next){
int to = e[i].to;
if (e[i].flow && dep[to] == dep[u]+1){
int x = dfs(to, min(e[i].flow, f1));
e[i].flow -= x; e[i^1].flow += x;
f1 -= x, f += x;
if (f1 == 0) return f;
}
}
if (!f) dep[u] = -2;
return f;
}
int maxflow(int s, int t){
int ans = 0;
while(bfs(s, t)){
ans += dfs(s, inf);
}
return ans;
}
int main() {
//freopen("in.txt", "r", stdin);
//freopen("out.txt", "w", stdout);
int x, y;
cin >> m >> n;
s = 0, t = n+1;
memset(head, -1, sizeof(head));
for(int i = 1; i <= m; i++) scanf("%d", &a[i]);
for(int i = 1; i <= n; i++){
scanf("%d", &x);
for(int j = 1; j <= x; j++) {
scanf("%d", &y);
ve[i].push_back(y);
}
scanf("%d", &y);
addedge(i, t, y);
}
for(int i = 1; i <= n; i++){
for(int j = 0; j < ve[i].size(); j++){
int v = ve[i][j];
if (!belong[v]) {
belong[v] = i;
addedge(s, i, a[v]);
}
else {
addedge(belong[v], i, inf);
belong[v] = i;
}
}
}
printf("%d\n", maxflow(s, t));
return 0;
}
标签：customer any another bec return line bfs written numbers
原文地址：https://www.cnblogs.com/ccut-ry/p/9932842.html
