【HDOJ】1914 The Stable Marriage Problem
稳定婚姻问题，Gale-Shapley算法可解。
1 /* 1914 */ 2 #include <iostream> 3 #include <sstream> 4 #include <string> 5 #include <map> 6 #include <queue> 7 #include <set> 8 #include <stack> 9 #include <vector> 10 #include <deque> 11 #include <algorithm> 12 #include <cstdio> 13 #include <cmath> 14 #include <ctime> 15 #include <cstring> 16 #include <climits> 17 #include <cctype> 18 #include <cassert> 19 #include <functional> 20 #include <iterator> 21 #include <iomanip> 22 using namespace std; 23 //#pragma comment(linker,"/STACK:102400000,1024000") 24 25 #define sti set<int> 26 #define stpii set<pair<int, int> > 27 #define mpii map<int,int> 28 #define vi vector<int> 29 #define pii pair<int,int> 30 #define vpii vector<pair<int,int> > 31 #define rep(i, a, n) for (int i=a;i<n;++i) 32 #define per(i, a, n) for (int i=n-1;i>=a;--i) 33 #define clr clear 34 #define pb push_back 35 #define mp make_pair 36 #define fir first 37 #define sec second 38 #define all(x) (x).begin(),(x).end() 39 #define SZ(x) ((int)(x).size()) 40 #define lson l, mid, rt<<1 41 #define rson mid+1, r, rt<<1|1 42 43 const int maxn = 30; 44 char s[40]; 45 char wname[40]; 46 int pref[maxn][maxn]; 47 int order[maxn][maxn]; 48 int nxt[maxn]; 49 int future_husband[maxn]; 50 int future_wife[maxn]; 51 queue<int> Q; 52 int n; 53 int ID[128]; 54 55 void engage(int man, int woman) { 56 int m = future_husband[woman]; 57 58 if (m) { 59 future_wife[m] = 0; 60 Q.push(m); 61 } 62 63 future_husband[woman] = man; 64 future_wife[man] = woman; 65 } 66 67 void solve() { 68 while (!Q.empty()) { 69 int man = Q.front(); 70 Q.pop(); 71 int woman = pref[man][nxt[man]++]; 72 if (!future_husband[woman]) { 73 engage(man, woman); 74 } else if (order[woman][man] < order[woman][future_husband[woman]]) { 75 engage(man, woman); 76 } else { 77 Q.push(man); 78 } 79 } 80 81 rep(i, 'a', 'z'+1) { 82 if (!ID[i]) 83 continue; 84 printf("%c %c\n", i, wname[future_wife[ID[i]]]); 85 } 86 } 87 88 int main() { 89 ios::sync_with_stdio(false); 90 #ifndef ONLINE_JUDGE 91 freopen("data.in", "r", stdin); 92 freopen("data.out", "w", stdout); 93 #endif 94 95 int t; 96 int nlc, nuc; 97 98 scanf("%d", &t); 99 while (t--) { 100 scanf("%d", &n); 101 memset(ID, 0, sizeof(ID)); 102 nlc = nuc = 0; 103 rep(i, 0, n+n) { 104 scanf("%s", s); 105 if (islower(s[0])) { 106 ID[s[0]] = ++nlc; 107 } else { 108 ID[s[0]] = ++nuc; 109 wname[nuc] = s[0]; 110 } 111 } 112 113 while (!Q.empty()) 114 Q.pop(); 115 116 int lid, uid; 117 118 rep(i, 0, n) { 119 scanf("%s", s); 120 lid = ID[s[0]]; 121 rep(j, 1, n+1) { 122 uid = ID[s[1+j]]; 123 pref[lid][j] = uid; 124 } 125 nxt[lid] = 1; 126 future_wife[lid] = 0; 127 Q.push(lid); 128 } 129 130 rep(i, 0, n) { 131 scanf("%s", s); 132 uid = ID[s[0]]; 133 rep(j, 1, n+1) { 134 lid = ID[s[1+j]]; 135 order[uid][lid] = j; 136 } 137 future_husband[uid] = 0; 138 } 139 solve(); 140 if (t) 141 putchar('\n'); 142 } 143 144 #ifndef ONLINE_JUDGE 145 printf("time = %d.\n", (int)clock()); 146 #endif 147 148 return 0; 149 }
