题目链接：http://acm.split.hdu.edu.cn/showproblem.php?pid=4185
题意：一片(n*10)*(n*10)的平面上有油（#）也有水（.），现在有规格为10*20的铲子（相当于每个铲子可以覆盖1*2或者2*1的平面）想要把油盖上，铲子不能相交。问如何分配才能把油尽可能多地覆盖到。
思路：给每个#编号，按照编号，油如果有相邻的，则给他们的编号建一条边。注意编号的范围变成600*600了，建图大一倍要注意。
1 /* 2 ━━━━━┒ギリギリ♂ eye！ 3 ┓┏┓┏┓┃キリキリ♂ mind！ 4 ┛┗┛┗┛┃＼○／ 5 ┓┏┓┏┓┃ / 6 ┛┗┛┗┛┃ノ) 7 ┓┏┓┏┓┃ 8 ┛┗┛┗┛┃ 9 ┓┏┓┏┓┃ 10 ┛┗┛┗┛┃ 11 ┓┏┓┏┓┃ 12 ┛┗┛┗┛┃ 13 ┓┏┓┏┓┃ 14 ┃┃┃┃┃┃ 15 ┻┻┻┻┻┻ 16 */ 17 #include <algorithm> 18 #include <iostream> 19 #include <iomanip> 20 #include <cstring> 21 #include <climits> 22 #include <complex> 23 #include <fstream> 24 #include <cassert> 25 #include <cstdio> 26 #include <bitset> 27 #include <vector> 28 #include <deque> 29 #include <queue> 30 #include <stack> 31 #include <ctime> 32 #include <set> 33 #include <map> 34 #include <cmath> 35 using namespace std; 36 #define fr first 37 #define sc second 38 #define cl clear 39 #define BUG puts("here!!!") 40 #define W(a) while(a--) 41 #define pb(a) push_back(a) 42 #define Rint(a) scanf("%d", &a) 43 #define Rs(a) scanf("%s", a) 44 #define Cin(a) cin >> a 45 #define FRead() freopen("in", "r", stdin) 46 #define FWrite() freopen("out", "w", stdout) 47 #define Rep(i, len) for(int i = 0; i < (len); i++) 48 #define For(i, a, len) for(int i = (a); i < (len); i++) 49 #define Cls(a) memset((a), 0, sizeof(a)) 50 #define Clr(a, x) memset((a), (x), sizeof(a)) 51 #define Full(a) memset((a), 0x7f7f7f, sizeof(a)) 52 #define lrt rt << 1 53 #define rrt rt << 1 | 1 54 #define pi 3.14159265359 55 #define RT return 56 #define lowbit(x) x & (-x) 57 #define onecnt(x) __builtin_popcount(x) 58 typedef long long LL; 59 typedef long double LD; 60 typedef unsigned long long ULL; 61 typedef pair<int, int> pii; 62 typedef pair<string, int> psi; 63 typedef pair<LL, LL> pll; 64 typedef map<string, int> msi; 65 typedef vector<int> vi; 66 typedef vector<LL> vl; 67 typedef vector<vl> vvl; 68 typedef vector<bool> vb; 69 70 const int maxn = 660; 71 const int inf = 0x3f3f3f3f; 72 int dx[4] = {1, -1, 0, 0}; 73 int dy[4] = {0, 0, 1, -1}; 74 int n; 75 char tmp[maxn]; 76 int order[maxn*maxn], ocnt; 77 int nu,nv; 78 int G[maxn][maxn], mp[maxn][maxn]; 79 bool vis[maxn*maxn]; 80 int linker[maxn*maxn]; 81 82 bool dfs(int u) { 83 Rep(v, nv) { 84 if(G[u][v] && !vis[v]) { 85 vis[v] = 1; 86 if(linker[v] == -1 || dfs(linker[v])) { 87 linker[v] = u; 88 return 1; 89 } 90 } 91 } 92 return 0; 93 } 94 95 int hungary() { 96 int ret = 0; 97 Clr(linker, -1); 98 Rep(u, nu) { 99 Cls(vis); 100 if(dfs(u)) ret++; 101 } 102 return ret; 103 } 104 105 int main() { 106 // FRead(); 107 int T, _ = 1; 108 Rint(T); 109 W(T) { 110 Rint(n); 111 Rep(i, n+10) Rep(j, n+10) mp[i][j] = inf; ocnt = 0; 112 Rep(i, n) { 113 Rs(tmp); 114 Rep(j, n) { 115 if(tmp[j] == '#') mp[i][j] = ocnt++; 116 } 117 } 118 nu = nv = ocnt; Cls(G); 119 Rep(i, n) { 120 Rep(j, n) { 121 if(mp[i][j] != inf) { 122 Rep(k, 4) { 123 int x = i + dx[k]; 124 int y = j + dy[k]; 125 if(mp[x][y] != inf) { 126 G[mp[i][j]][mp[x][y]] = 1; 127 } 128 } 129 } 130 } 131 } 132 printf("Case %d: %d ", _++, hungary()/2); 133 } 134 RT 0; 135 }
1 /* 2 ━━━━━┒ギリギリ♂ eye！ 3 ┓┏┓┏┓┃キリキリ♂ mind！ 4 ┛┗┛┗┛┃＼○／ 5 ┓┏┓┏┓┃ / 6 ┛┗┛┗┛┃ノ) 7 ┓┏┓┏┓┃ 8 ┛┗┛┗┛┃ 9 ┓┏┓┏┓┃ 10 ┛┗┛┗┛┃ 11 ┓┏┓┏┓┃ 12 ┛┗┛┗┛┃ 13 ┓┏┓┏┓┃ 14 ┃┃┃┃┃┃ 15 ┻┻┻┻┻┻ 16 */ 17 #include <algorithm> 18 #include <iostream> 19 #include <iomanip> 20 #include <cstring> 21 #include <climits> 22 #include <complex> 23 #include <fstream> 24 #include <cassert> 25 #include <cstdio> 26 #include <bitset> 27 #include <vector> 28 #include <deque> 29 #include <queue> 30 #include <stack> 31 #include <ctime> 32 #include <set> 33 #include <map> 34 #include <cmath> 35 using namespace std; 36 #define fr first 37 #define sc second 38 #define cl clear 39 #define BUG puts("here!!!") 40 #define W(a) while(a--) 41 #define pb(a) push_back(a) 42 #define Rint(a) scanf("%d", &a) 43 #define Rs(a) scanf("%s", a) 44 #define Cin(a) cin >> a 45 #define FRead() freopen("in", "r", stdin) 46 #define FWrite() freopen("out", "w", stdout) 47 #define Rep(i, len) for(int i = 0; i < (len); i++) 48 #define For(i, a, len) for(int i = (a); i < (len); i++) 49 #define Cls(a) memset((a), 0, sizeof(a)) 50 #define Clr(a, x) memset((a), (x), sizeof(a)) 51 #define Full(a) memset((a), 0x7f7f7f, sizeof(a)) 52 #define lrt rt << 1 53 #define rrt rt << 1 | 1 54 #define pi 3.14159265359 55 #define RT return 56 #define lowbit(x) x & (-x) 57 #define onecnt(x) __builtin_popcount(x) 58 typedef long long LL; 59 typedef long double LD; 60 typedef unsigned long long ULL; 61 typedef pair<int, int> pii; 62 typedef pair<string, int> psi; 63 typedef pair<LL, LL> pll; 64 typedef map<string, int> msi; 65 typedef vector<int> vi; 66 typedef vector<LL> vl; 67 typedef vector<vl> vvl; 68 typedef vector<bool> vb; 69 70 const int maxn = 660; 71 int dx[4] = {1, -1, 0, 0}; 72 int dy[4] = {0, 0, 1, -1}; 73 int n; 74 char tmp[maxn]; 75 int order[maxn*maxn], ocnt; 76 const int inf = 0x3f3f3f3f; 77 int nx,ny; 78 int G[maxn][maxn], mp[maxn][maxn]; 79 int linker[maxn*maxn],lx[maxn*maxn],ly[maxn*maxn]; 80 int slack[maxn*maxn]; 81 bool visx[maxn*maxn],visy[maxn*maxn]; 82 83 bool dfs(int x) { 84 visx[x] = true; 85 for(int y = 0; y < ny; y++) { 86 if(visy[y])continue; 87 int tmp = lx[x] + ly[y] - G[x][y]; 88 if(tmp == 0) { 89 visy[y] = true; 90 if(linker[y] == -1 || dfs(linker[y])) { 91 linker[y] = x; 92 return true; 93 } 94 } 95 else if(slack[y] > tmp) 96 slack[y] = tmp; 97 } 98 return false; 99 } 100 int km() { 101 memset(linker,-1,sizeof(linker)); 102 memset(ly,0,sizeof(ly)); 103 for(int i = 0;i < nx;i++) { 104 lx[i] = -inf; 105 for(int j = 0;j < ny;j++) 106 if(G[i][j] > lx[i]) 107 lx[i] = G[i][j]; 108 } 109 for(int x = 0;x < nx;x++) { 110 for(int i = 0;i < ny;i++) 111 slack[i] = inf; 112 while(true) { 113 memset(visx,false,sizeof(visx)); 114 memset(visy,false,sizeof(visy)); 115 if(dfs(x))break; 116 int d = inf; 117 for(int i = 0;i < ny;i++) 118 if(!visy[i] && d > slack[i]) 119 d = slack[i]; 120 for(int i = 0;i < nx;i++) 121 if(visx[i]) 122 lx[i] -= d; 123 for(int i = 0;i < ny;i++) { 124 if(visy[i])ly[i] += d; 125 else slack[i] -= d; 126 } 127 } 128 } 129 int res = 0; 130 for(int i = 0;i < ny;i++) 131 if(linker[i] != -1) 132 res += G[linker[i]][i]; 133 return res; 134 } 135 136 int main() { 137 // FRead(); 138 int T, _ = 1; 139 Rint(T); 140 W(T) { 141 Rint(n); 142 Rep(i, n+10) Rep(j, n+10) mp[i][j] = inf; ocnt = 0; 143 Rep(i, n) { 144 Rs(tmp); 145 Rep(j, n) { 146 if(tmp[j] == '#') mp[i][j] = ocnt++; 147 } 148 } 149 nx = ny = ocnt; Cls(G); 150 Rep(i, n) { 151 Rep(j, n) { 152 if(mp[i][j] != inf) { 153 Rep(k, 4) { 154 int x = i + dx[k]; 155 int y = j + dy[k]; 156 if(mp[x][y] != inf) { 157 G[mp[i][j]][mp[x][y]] = 1; 158 } 159 } 160 } 161 } 162 } 163 printf("Case %d: %d ", _++, km()/2); 164 } 165 RT 0; 166 }