ZOJ 3209 Treasure Map 精确覆盖

  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 = 10205;
 20 const int maxNode = 520005;
 21 struct DLX {
 22     int L[maxNode], R[maxNode], U[maxNode], D[maxNode], row[maxNode], col[maxNode];
 23     int S[maxn], H[maxn], deep, sz, n, m, num;
 24     void remove(int c) {
 25         L[R[c]] = L[c];
 26         R[L[c]] = R[c];
 27         for(int i = D[c]; i!=c; i = D[i])
 28             for(int j = R[i]; j!=i; j = R[j]) {
 29                 U[D[j]] = U[j];
 30                 D[U[j]] = D[j];
 31                 S[col[j]]--;
 32             }
 33     }
 34     void resume(int c) {
 35         for(int i = U[c]; i!=c; i = U[i])
 36             for(int j = L[i]; j!=i; j = L[j]) {
 37                 S[col[j]]++;
 38                 D[U[j]] = j;
 39                 U[D[j]] = j;
 40             }
 41         R[L[c]] = c;
 42         L[R[c]] = c;
 43     }
 44     void dfs(int d) {
 45         if(d>=deep)
 46             return ;
 47         if(R[0] == 0) {
 48             deep = min(d, deep);
 49             return ;
 50         }
 51         int c = R[0];
 52         for(int i = R[0]; i!=0; i = R[i])
 53             if(S[c]>S[i])
 54                 c = i;
 55         remove(c);
 56         for(int i = D[c]; i!=c; i = D[i]) {
 57             for(int j = R[i]; j!=i; j = R[j])
 58                 remove(col[j]);
 59             dfs(d+1);
 60             for(int j = L[i]; j!=i; j = L[j])
 61                 resume(col[j]);
 62         }
 63         resume(c);
 64         return ;
 65     }
 66     void add(int r, int c) {
 67         sz++;
 68         col[sz] = c;
 69         S[c]++;
 70         U[sz] = U[c];
 71         D[sz] = c;
 72         D[U[c]] = sz;
 73         U[c] = sz;
 74         if(~H[r]) {
 75             R[sz] = H[r];
 76             L[sz] = L[H[r]];
 77             L[R[sz]] = sz;
 78             R[L[sz]] = sz;
 79         } else {
 80             H[r] = L[sz] = R[sz] = sz;
 81         }
 82     }
 83     void init(){
 84         mem1(H);
 85         for(int i = 0; i<=n; i++) {
 86             R[i] = i+1;
 87             L[i] = i-1;
 88             D[i] = U[i] = i;
 89         }
 90         R[n] = 0;
 91         L[0] = n;
 92         mem(S);
 93         sz = n;
 94         deep = inf;
 95     }
 96     void solve() {
 97         scanf("%d%d%d", &n, &m, &num);
 98         n *= m;
 99         init();
100         int x1, y1, x2, y2;
101         int cnt = 1;
102         while(num--) {
103             scanf("%d%d%d%d", &x1, &y1, &x2, &y2);
104             for(int i = x1+1; i<=x2; i++) {
105                 for(int j = y1+1; j<=y2; j++) {
106                     add(cnt, (i-1)*m+j);
107                 }
108             }
109             cnt++;
110         }
111         dfs(0);
112         if(deep == inf) {
113             puts("-1");
114         } else {
115             printf("%d\n", deep);
116         }
117     }
118 }dlx;
119 int main()
120 {
121     int t;
122     cin>>t;
123     while(t--) {
124         dlx.solve();
125     }
126 }