UVA - 10308 - Roads in the North （DFS）

標籤：acm   uva   gcd   

題目傳送：UVA - 10308

思路：就是樹的遍曆，DFS即可，注意輸入

AC代碼：

#include <cstdio>#include <cstring>#include <iostream>#include <string>#include <sstream>#include <algorithm>#include <cmath>#include <queue>#include <stack>#include <vector>#include <map>#include <set>#include <deque>#include <cctype>#define LL long long#define INF 0x7fffffffusing namespace std;struct node {int e, w;node(int _e, int _w) : e(_e), w(_w) { }}; const int maxn = 10010;vector<node> G[maxn];int ans;int dfs(int u, int fa) {int maxx = 0;//maxx表示當前結點到葉子結點的最大權值int anss;//anss表示當前結點到葉子結點的權值 int len = G[u].size();for(int i = 0; i < len; i ++) {if(G[u][i].e != fa) {anss = dfs(G[u][i].e, u) + G[u][i].w;ans = max(ans, anss + maxx);//更新答案 maxx = max(anss, maxx);//更新最大權值 }}return maxx;}int main() {string s;    while (!cin.eof()) {    for(int i = 0; i < maxn; i ++)G[i].clear();        getline(cin, s);        while (s.length() > 0 && !cin.eof())        {            stringstream ss;            ss << s;            int u, v, w;            ss >> u >> v >> w;            G[u].push_back(node(v, w));            G[v].push_back(node(u, w));            getline(cin, s);        }        ans = 0;dfs(1, -1);printf("%d\n", ans);    }return 0;}

UVA - 10308 - Roads in the North （DFS）