hdu 2112 HDU Today

原题链接：http://acm.hdu.edu.cn/showproblem.php?pid=2112

最短路。。

#include<algorithm>#include<iostream>#include<cstdlib>#include<cstring>#include<cstdio>#include<vector>#include<string>#include<queue>#include<map>using std::map;using std::cin;using std::cout;using std::endl;using std::find;using std::sort;using std::pair;using std::vector;using std::string;using std::multimap;using std::priority_queue;#define pb(e) push_back(e)#define sz(c) (int)(c).size()#define mp(a, b) make_pair(a, b)#define all(c) (c).begin(), (c).end()#define iter(c) decltype((c).begin())#define cls(arr,val) memset(arr,val,sizeof(arr))#define cpresent(c, e) (find(all(c), (e)) != (c).end())#define rep(i, n) for (int i = 0; i < (int)(n); i++)#define tr(c, i) for (iter(c) i = (c).begin(); i != (c).end(); ++i)const int N = 20010;typedef unsigned long long ull;struct P {int w, v;P(int i = 0, int j = 0) :w(i), v(j) {}inline bool operator<(const P &a) const {return w > a.w;}};struct Node { int to, w, next; };struct Dijkstra {Node G[N];map<string, int> A;int start, end, tot, dist[210], head[N];inline void init() {tot = 0, A.clear();cls(head, -1), cls(dist, 0x3f);}inline void add_edge(int u, int v, int w) {G[tot] = { v, w, head[u] }; head[u] = tot++;}inline void built(int n) {char str[4][32];int u, v, w, k = 1;scanf("%s %s", str[0], str[1]);A[str[0]] = k++, A[str[1]] = k++;rep(i, n) {scanf("%s %s %d", str[2], str[3], &w);if (A.find(str[2]) == A.end()) A[str[2]] = k++;if (A.find(str[3]) == A.end()) A[str[3]] = k++;u = A[str[2]], v = A[str[3]];add_edge(u, v, w), add_edge(v, u, w);}start = A[str[0]], end = A[str[1]];}inline void dijkstra() {dist[start] = 0;priority_queue<P> q;q.push(P(0, start));while (!q.empty()) {P t = q.top(); q.pop();int u = t.v;if (dist[u] < t.w) continue;for (int i = head[u]; ~i; i = G[i].next) {int &w = dist[G[i].to];if (w > dist[u] + G[i].w) {w = dist[u] + G[i].w;q.push(P(w, G[i].to));}}}printf("%d\n", dist[end] == (int)0x3f3f3f3f ? -1 : dist[end]);}}go;int main() {#ifdef LOCALfreopen("in.txt", "r", stdin);freopen("out.txt", "w+", stdout);#endifint n;while (~scanf("%d", &n) && n != -1) {go.init();go.built(n);go.dijkstra();}return 0;}