HDU 4888 Redraw Beautiful Drawings

  1 #include <bits/stdc++.h>
  2 using namespace std;
  3 const int maxn = 810;
  4 const int INF = 0x3f3f3f3f;
  5 struct arc{
  6     int to,flow,next;
  7     arc(int x = 0,int y = 0,int z = -1){
  8         to = x;
  9         flow = y;
 10         next = z;
 11     }
 12 }e[maxn*maxn<<1];
 13 int head[maxn],d[maxn],cur[maxn],tot,S,T,n,m,k;
 14 bool vis[maxn];
 15 void add(int u,int v,int flow){
 16     e[tot] = arc(v,flow,head[u]);
 17     head[u] = tot++;
 18     e[tot] = arc(u,0,head[v]);
 19     head[v] = tot++;
 20 }
 21 bool bfs(){
 22     queue<int>q;
 23     memset(d,-1,sizeof d);
 24     d[S] = 1;
 25     q.push(S);
 26     while(!q.empty()){
 27         int u = q.front();
 28         q.pop();
 29         for(int i = head[u]; ~i; i = e[i].next){
 30             if(e[i].flow && d[e[i].to] == -1){
 31                 d[e[i].to] = d[u] + 1;
 32                 q.push(e[i].to);
 33             }
 34         }
 35     }
 36     return d[T] > -1;
 37 }
 38 int dfs(int u,int low){
 39     if(u == T) return low;
 40     int tmp = 0,a;
 41     for(int &i = cur[u]; ~i; i = e[i].next){
 42         if(e[i].flow && d[e[i].to] == d[u] + 1&&(a=dfs(e[i].to,min(low,e[i].flow)))){
 43             e[i].flow -= a;
 44             e[i^1].flow += a;
 45             low -= a;
 46             tmp += a;
 47             if(!low) break;
 48         }
 49     }
 50     if(!tmp) d[u] = -1;
 51     return tmp;
 52 }
 53 int dinic(){
 54     int ret = 0;
 55     while(bfs()){
 56         memcpy(cur,head,sizeof head);
 57         ret += dfs(S,INF);
 58     }
 59     return ret;
 60 }
 61 bool dfs2(int u,int fa){
 62     if(vis[u]) return true;
 63     vis[u] = true;
 64     for(int i = head[u]; ~i; i = e[i].next)
 65         if(e[i].flow && e[i].to != fa && dfs2(e[i].to,u)) return true;
 66     return vis[u] = false;
 67 }
 68 int main(){
 69     int tmp,sum,ans[maxn];
 70     while(~scanf("%d %d %d",&n,&m,&k)){
 71         memset(head,-1,sizeof head);
 72         S = n + m + 1;
 73         T = S + 1;
 74         sum = tot = 0;
 75         for(int i = 1; i <= n; ++i){
 76             scanf("%d",&tmp);
 77             add(S,i,tmp);
 78             sum += tmp;
 79             for(int j = 1; j <= m; ++j)
 80                 add(i,j+n,k);
 81         }
 82         for(int i = 1; i <= m; ++i){
 83             scanf("%d",&tmp);
 84             add(i+n,T,tmp);
 85         }
 86         sum -= dinic();
 87         if(sum) puts("Impossible");
 88         else{
 89             bool flag = false;
 90             memset(vis,false,sizeof vis);
 91             for(int i = 1; i <= n; ++i)
 92                 if(flag = dfs2(i,-1)) break;
 93             if(flag) puts("Not Unique");
 94             else{
 95                 puts("Unique");
 96                 for(int i = 1; i <= n; ++i){
 97                     for(int j = head[i]; ~j; j = e[j].next)
 98                         if(e[j].to > i) ans[e[j].to] = e[j^1].flow;
 99                     for(int i = 1; i <= m; ++i)
100                         printf("%d%c",ans[i+n],i==m?‘\n‘:‘ ‘);
101                 }
102             }
103         }
104     }
105     return 0;
106 }
107 /*
108 4 2 2
109 2 2 5 0
110 5 4
111 */