1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 #include <cstdlib> 5 #include <algorithm> 6 #include <queue> 7 #include <vector> 8 #include <stack> 9 #include <map> 10 #include <set> 11 #include <cmath> 12 #include <cctype> 13 #include <ctime> 14 #include <bitset> 15 16 using namespace std; 17 18 #define REP(i, n) for (int i = 0; i < (n); ++i) 19 #define eps 1e-9 20 21 typedef long long ll; 22 typedef pair<int, int> pii; 23 24 const int INF = 0x7fffffff; 25 const int maxn = 1e5; 26 int n, edge; 27 int head[maxn], to[maxn], Next[maxn], dp[2][maxn], in[maxn]; 28 29 inline void init() { edge = 0; memset(head, -1, sizeof(head)); } 30 inline void add_edge(int u, int v) { 31 to[edge] = v; Next[edge] = head[u]; head[u] = edge++; 32 } 33 void dfs(int u, int fa) { 34 for (int i = head[u]; i != -1; i = Next[i]) { 35 if (to[i] == fa) { continue; } dfs(to[i], u); 36 dp[0][u] += max(dp[0][to[i]], dp[1][to[i]]); 37 dp[1][u] += dp[0][to[i]]; 38 } 39 } 40 41 int main() { 42 #ifdef __AiR_H 43 freopen("in.txt", "r", stdin); 44 // freopen("out.txt", "w", stdout); 45 #endif // __AiR_H 46 while (scanf("%d", &n) != EOF) { 47 init(); int a, b; memset(dp, 0, sizeof(dp)); 48 for (int i = 1; i <= n; ++i) { scanf("%d", &dp[1][i]); } 49 while (scanf("%d %d", &a, &b) != EOF) { 50 if (a == 0 && b == 0) { break; } 51 add_edge(a, b); add_edge(b, a); ++in[a]; //b是a的顶头上司 52 } 53 for (int i = 1; i <= n; ++i) { 54 if (in[i]) { continue; } 55 dfs(i, 0); printf("%d\n", max(dp[0][i], dp[1][i])); break; 56 } 57 } 58 #ifdef __AiR_H 59 printf("Time used = %.2fs\n", (double)clock() / CLOCKS_PER_SEC); 60 #endif // __AiR_H 61 return 0; 62 }
