UVaLive6039 Uva1668 Let's Go Green

一开始考虑所有边都是单独的一条路径

然后尽量多的合并

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<cstdlib>
 4 #include<algorithm>
 5 #include<iostream>
 6
 7 using namespace std;
 8
 9 void setIO(const string& s) {
10     freopen((s + ".in").c_str(), "r", stdin);
11     freopen((s + ".out").c_str(), "w", stdout);
12 }
13 template<typename Q> Q read(Q& x) {
14     static char c, f;
15     for(f = 0; c = getchar(), !isdigit(c); ) if(c == ‘-‘) f = 1;
16     for(x = 0; isdigit(c); c = getchar()) x = x * 10 + c - ‘0‘;
17     if(f) x = -x;
18     return x;
19 }
20 template<typename Q> Q read() {
21     static Q x; read(x); return x;
22 }
23
24 const int N = 100000 + 10;
25 int main() {
26 #ifdef DEBUG
27     freopen("in.txt", "r", stdin);
28     freopen("out.txt", "w", stdout);
29 #endif
30
31     static int du[N], mx[N];
32     int T = read<int>();
33     for(int cas = 1; cas <= T; cas++) {
34         memset(du, 0, sizeof du);
35         memset(mx, 0, sizeof mx);
36         int ans = 0;
37         int u, v, w, n = read<int>();
38         for(int i = 1; i < n; i++) {
39             read(u), read(v), read(w);
40             du[u] += w, du[v] += w;
41             mx[u] = max(mx[u], w);
42             mx[v] = max(mx[v], w);
43             ans += w;
44         }
45
46         for(int u = 1; u <= n; u++) {
47             if((mx[u] << 1) <= du[u]) ans -= du[u] >> 1;
48             else ans -= du[u] - mx[u];
49         }
50
51         printf("Case #%d: %d\n", cas, ans);
52     }
53
54     return 0;
55 }

UVaLive6039 Uva1668 Let's Go Green