题目链接:点击打开链接
首行一个数T(T <= 40),代表数据总数,接下来有T组数据。
每组数据:
第一行两个数N,M(1 <= N,M <= 50)
接下来N行,每行M个数(范围是0-10000的整数)
接下来一行有N个数Ki,表示第i行至少选Ki个元素(0 <= Ki <= M)
最后一行有M个数Kj,表示第j列至少选Kj个元素(0 <= Kj <= N)
1 4 4 1 1 1 1 1 10 10 10 1 10 10 10 1 10 10 10 1 1 1 1 1 1 1 1
6
n行作为左端点 m作为右端点建一个二部图
n个点连到源点 流量为inf ,费用为0
m个点连到汇点 流量为inf 费用为0
n个点和m个点之间连一条费用为 mp[i][j] ,流量为1的点
--------------------------- 以上是普通建图-----------------------
为了达到有下界的效果
给下界对应的点加一个费用为-inf,流量为ki的边,这样让费用流强制把所有费用为-inf的边先跑
意思也就是先使得下界的边满流。
当费用>0时, 说明这次跑的边中不存在有下界的边,那么就相当于下界的边已经满流,所以直接终止费用流
#include<iostream> #include<cstdio> #include<cstring> #include<string> #include<algorithm> #include<map> #include<queue> #include<stack> #include<set> #include<cmath> #include<vector> #define eps 1e-9 #define pi acos(-1.0) using namespace std; #define ll int #define inf 0x3f3f3f3f #define Inf 0x3FFFFFFFFFFFFFFFLL #define N 105 #define M 1005 struct Edge { ll from,to,cap,cost,nex; Edge(){} Edge(ll from,ll to,ll cap,ll cost,ll next):from(from),to(to),cap(cap),cost(cost),nex(next){} }edges[M<<1]; ll head[N], edgenum; ll d[N], a[N], p[N]; bool inq[N]; void add(ll from,ll to,ll cap,ll cost) { edges[edgenum] = Edge(from,to,cap,cost,head[from]); head[from] = edgenum++; edges[edgenum] = Edge(to,from,0,-cost,head[to]); head[to] = edgenum++; } bool spfa(ll s, ll t, ll &flow, ll &cost) { for(ll i = 0; i <= t; i++) d[i] = inf; memset(inq, 0, sizeof inq); queue<ll>q; q.push(s); d[s] = 0; a[s] = inf; while(!q.empty()) { ll u = q.front(); q.pop(); inq[u] = 0; for(ll i = head[u]; ~i; i = edges[i].nex) { Edge &e = edges[i]; if(e.cap && d[e.to] > d[u] + e.cost) { d[e.to] = d[u] + e.cost; p[e.to] = i; a[e.to] = min(a[u], e.cap); if(!inq[e.to]) {inq[e.to]=1; q.push(e.to);} } } } if(d[t]>0) return false; cost += d[t] * a[t]; flow += a[t]; ll u = t; while(u != s){ edges[ p[u] ].cap -= a[t]; edges[p[u]^1].cap += a[t]; u = edges[p[u]^1].to; } return true; } ll Mincost(ll s,ll t){//返回最小费用 ll flow = 0, cost = 0; while(spfa(s, t, flow, cost)); return cost; } void init(){memset(head,-1,sizeof head); edgenum = 0;} int n,m; int mp[55][55]; int h[55], l[55]; void input(){ scanf("%d %d",&n,&m); for(int i = 1; i <= n; i++) for(int j = 1; j <= m; j++) scanf("%d",&mp[i][j]); for(int i = 1; i <= n; i++)scanf("%d",&h[i]); for(int i = 1; i <= m; i++)scanf("%d",&l[i]); } #define hehe 100000 int main(){ int T, i, j;scanf("%d",&T); while(T--){ input(); init(); int from = 0, to = n+m+1; int les = 0; for(i = 1; i <= n; i++) { les += h[i]; add(from, i, h[i], -hehe); add(from, i, inf, 0); } for(i = 1; i <= m; i++) { les += l[i]; add(n + i, to, l[i], -hehe); add(n + i, to, inf, 0); } for(i = 1; i <= n; i++) for(j = 1; j <= m; j++) add(i, n+j, 1, mp[i][j]); printf("%d\n", Mincost(from, to) + hehe*les); } return 0; } /* http://acdream.info/onecontest/1080#problem-H http://paste.ubuntu.com/7930356/#userconsent# */
Acdream 1171 Matrix sum 上下界费用流,布布扣,bubuko.com
Acdream 1171 Matrix sum 上下界费用流
原文:http://blog.csdn.net/qq574857122/article/details/38353251