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题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1827
缩点后统计入度和当前强连通分量中最小花费,然后记录入度为0的点的个数和花费和就行了。
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 Rll(a) scanf("%I64d", &a) 44 #define Rs(a) scanf("%s", a) 45 #define Cin(a) cin >> a 46 #define FRead() freopen("in", "r", stdin) 47 #define FWrite() freopen("out", "w", stdout) 48 #define Rep(i, len) for(int i = 0; i < (len); i++) 49 #define For(i, a, len) for(int i = (a); i < (len); i++) 50 #define Cls(a) memset((a), 0, sizeof(a)) 51 #define Clr(a, x) memset((a), (x), sizeof(a)) 52 #define Full(a) memset((a), 0x7f7f, sizeof(a)) 53 #define pi 3.14159265359 54 #define RT return 55 #define lowbit(x) x & (-x) 56 #define onenum(x) __builtin_popcount(x) 57 typedef long long LL; 58 typedef long double LD; 59 typedef unsigned long long ULL; 60 typedef pair<int, int> pii; 61 typedef pair<string, int> psi; 62 typedef map<string, int> msi; 63 typedef vector<int> vi; 64 typedef vector<LL> vl; 65 typedef vector<vl> vvl; 66 typedef vector<bool> vb; 67 68 const int maxn = 1010; 69 const int maxm = 2020; 70 const int inf = 0x7f7f7f; 71 int n, m; 72 vector<int> G[maxn]; 73 int vis[maxn][maxn]; 74 int w[maxn]; 75 int dfn[maxn], low[maxn], idx; 76 int st[maxn], top; 77 int belong[maxn], bcnt; 78 int in[maxn], out[maxn]; 79 int cost[maxn]; 80 81 void tarjan(int u) { 82 int v = u; 83 dfn[u] = low[u] = ++idx; 84 vis[0][u] = 1; st[++top] = u; 85 Rep(i, G[u].size()) { 86 v = G[u][i]; 87 if(!dfn[v]) { 88 tarjan(v); 89 low[u] = min(low[u], low[v]); 90 } 91 else if(vis[0][v]) low[u] = min(low[u], dfn[v]); 92 } 93 if(low[u] == dfn[u]) { 94 bcnt++; 95 do { 96 v = st[top--]; 97 vis[0][v] = 0; 98 belong[v] = bcnt; 99 } while(u != v); 100 } 101 } 102 103 int main() { 104 // FRead(); 105 int u, v; 106 while(~Rint(n) && ~Rint(m)) { 107 Cls(dfn); Cls(low); Cls(w); 108 Cls(st); Cls(vis); top = 0; 109 Cls(belong); bcnt = 0; idx = 0; 110 Cls(in); Cls(out); 111 For(i, 1, n+1) { 112 Rint(w[i]); 113 G[i].cl(); 114 cost[i] = inf; 115 } 116 Rep(i, m) { 117 Rint(u); Rint(v); 118 G[u].pb(v); 119 } 120 For(i, 1, n+1) if(!dfn[i]) tarjan(i); 121 Cls(vis); 122 For(u, 1, n+1) { 123 cost[belong[u]] = min(cost[belong[u]], w[u]); 124 Rep(i, G[u].size()) { 125 int v = G[u][i]; 126 if(belong[u] == belong[v]) continue; 127 in[belong[v]]++; 128 out[belong[u]]++; 129 } 130 } 131 int ret1 = 0, ret2 = 0; 132 For(i, 1, bcnt+1) { 133 if(in[i] == 0) { 134 ret1++; 135 ret2 += cost[i]; 136 } 137 } 138 printf("%d %d\n", ret1, ret2); 139 } 140 RT 0; 141 }
[HDOJ1827]Summer Holiday(强连通分量,缩点)
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原文地址:http://www.cnblogs.com/vincentX/p/5533761.html