hdu 4888 Redraw Beautiful Drawings 网络流

  1 #include<bits/stdc++.h>
  2 using namespace std;
  3 #define pb(x) push_back(x)
  4 #define ll long long
  5 #define mk(x, y) make_pair(x, y)
  6 #define lson l, m, rt<<1
  7 #define mem(a) memset(a, 0, sizeof(a))
  8 #define rson m+1, r, rt<<1|1
  9 #define mem1(a) memset(a, -1, sizeof(a))
 10 #define mem2(a) memset(a, 0x3f, sizeof(a))
 11 #define rep(i, a, n) for(int i = a; i<n; i++)
 12 #define ull unsigned long long
 13 typedef pair<int, int> pll;
 14 const double PI = acos(-1.0);
 15 const double eps = 1e-8;
 16 const int mod = 1e9+7;
 17 const int inf = 1061109567;
 18 const int dir[][2] = { {-1, 0}, {1, 0}, {0, -1}, {0, 1} };
 19 const int maxn = 1e6+5;
 20 int q[maxn*2], head[maxn*2], dis[maxn/10], s, t, num, vis[1005], cnt, col[405], row[405], g[405][405];
 21 struct node
 22 {
 23     int to, nextt, c;
 24     node(){}
 25     node(int to, int nextt, int c):to(to), nextt(nextt), c(c){}
 26 }e[maxn*2];
 27 void init() {
 28     num = cnt = 0;
 29     mem1(head);
 30     mem(vis);
 31 }
 32 void add(int u, int v, int c) {
 33     e[num] = node(v, head[u], c); head[u] = num++;
 34     e[num] = node(u, head[v], 0); head[v] = num++;
 35 }
 36 int bfs() {
 37     mem(dis);
 38     dis[s] = 1;
 39     int st = 0, ed = 0;
 40     q[ed++] = s;
 41     while(st<ed) {
 42         int u = q[st++];
 43         for(int i = head[u]; ~i; i = e[i].nextt) {
 44             int v = e[i].to;
 45             if(!dis[v]&&e[i].c) {
 46                 dis[v] = dis[u]+1;
 47                 if(v == t)
 48                     return 1;
 49                 q[ed++] = v;
 50             }
 51         }
 52     }
 53     return 0;
 54 }
 55 int dfs(int u, int limit) {
 56     if(u == t) {
 57         return limit;
 58     }
 59     int cost = 0;
 60     for(int i = head[u]; ~i; i = e[i].nextt) {
 61         int v = e[i].to;
 62         if(e[i].c&&dis[v] == dis[u]+1) {
 63             int tmp = dfs(v, min(limit-cost, e[i].c));
 64             if(tmp>0) {
 65                 e[i].c -= tmp;
 66                 e[i^1].c += tmp;
 67                 cost += tmp;
 68                 if(cost == limit)
 69                     break;
 70             } else {
 71                 dis[v] = -1;
 72             }
 73         }
 74     }
 75     return cost;
 76 }
 77 int dinic() {
 78     int ans = 0;
 79     while(bfs()) {
 80         ans += dfs(s, inf);
 81     }
 82     return ans;
 83 }
 84 int dfs1(int u, int fa) {
 85     if(vis[u])
 86         return 1;
 87     vis[u] = 1;
 88     for(int i = head[u]; ~i; i = e[i].nextt) {
 89         int v = e[i].to;
 90         if(v==fa||v==s||v==t) {
 91             continue;
 92         }
 93         if(e[i].c) {
 94             if(dfs1(v, u))
 95                 return 1;
 96         }
 97     }
 98     vis[u] = 0;
 99     return 0;
100 }
101 int main()
102 {
103     int n, m, x, limit;
104     while(~scanf("%d%d%d", &n, &m, &limit)) {
105         init();
106         int sum1 = 0, sum2 = 0;
107         s = 0, t = n+m+1;
108         for(int i = 1; i<=n; i++) {
109             scanf("%d", &x);
110             add(s, i, x);
111             sum2+=x;
112             for(int j = 1; j<=m; j++) {
113                 add(i, j+n, limit);
114             }
115         }
116         for(int i = 1; i<=m; i++) {
117             scanf("%d", &x);
118             add(i+n, t, x);
119             sum1+=x;
120         }
121         int ans = dinic(), flag = 0;
122         if(ans != sum1 || sum2!=ans) {
123             puts("Impossible");
124             continue;
125         }
126         for(int i = 1; i<=n; i++) {
127             if(dfs1(i, -1)) {
128                 flag = 1;
129                 break;
130             }
131         }
132         if(flag) {
133             puts("Not Unique");
134             continue;
135         }
136         for(int u = 1; u<=n; u++) {
137             for(int i = head[u]; ~i; i = e[i].nextt) {
138                 int v = e[i].to;
139                 if(v>n&&v<=n+m) {
140                     g[u][v-n] = limit-e[i].c;
141                 }
142             }
143         }
144         puts("Unique");
145         for(int i = 1; i<=n; i++) {
146             for(int j = 1; j<m; j++) {
147                 printf("%d ", g[i][j]);
148             }
149             printf("%d\n", g[i][m]);
150         }
151     }
152     return 0;
153 }