题目链接：http://acm.split.hdu.edu.cn/showproblem.php?pid=2255
题意：很明显了，连图都是明摆着的。带权值的最大匹配，直接用km算法。
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 = 330; 71 const int inf = 0x3f3f3f3f; 72 int n; 73 int nx,ny; 74 int G[maxn][maxn], mp[maxn][maxn]; 75 int linker[maxn],lx[maxn],ly[maxn]; 76 int slack[maxn]; 77 bool visx[maxn],visy[maxn]; 78 79 bool dfs(int x) { 80 visx[x] = true; 81 for(int y = 0; y < ny; y++) { 82 if(visy[y])continue; 83 int tmp = lx[x] + ly[y] - G[x][y]; 84 if(tmp == 0) { 85 visy[y] = true; 86 if(linker[y] == -1 || dfs(linker[y])) { 87 linker[y] = x; 88 return true; 89 } 90 } 91 else if(slack[y] > tmp) 92 slack[y] = tmp; 93 } 94 return false; 95 } 96 int km() { 97 memset(linker,-1,sizeof(linker)); 98 memset(ly,0,sizeof(ly)); 99 for(int i = 0;i < nx;i++) { 100 lx[i] = -inf; 101 for(int j = 0;j < ny;j++) 102 if(G[i][j] > lx[i]) 103 lx[i] = G[i][j]; 104 } 105 for(int x = 0;x < nx;x++) { 106 for(int i = 0;i < ny;i++) 107 slack[i] = inf; 108 while(true) { 109 memset(visx,false,sizeof(visx)); 110 memset(visy,false,sizeof(visy)); 111 if(dfs(x))break; 112 int d = inf; 113 for(int i = 0;i < ny;i++) 114 if(!visy[i] && d > slack[i]) 115 d = slack[i]; 116 for(int i = 0;i < nx;i++) 117 if(visx[i]) 118 lx[i] -= d; 119 for(int i = 0;i < ny;i++) { 120 if(visy[i])ly[i] += d; 121 else slack[i] -= d; 122 } 123 } 124 } 125 int res = 0; 126 for(int i = 0;i < ny;i++) 127 if(linker[i] != -1) 128 res += G[linker[i]][i]; 129 return res; 130 } 131 132 int main() { 133 // FRead(); 134 while(~Rint(n)) { 135 nx = ny = n; 136 Rep(i, n) { 137 Rep(j, n) { 138 Rint(G[i][j]); 139 } 140 } 141 printf("%d ", km()); 142 } 143 RT 0; 144 }
