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myCpps/!-OJcreater.cpp

@@ -12,7 +12,7 @@
 using namespace std;
 
 //***************************************
-const string CPPfile = "travelInDesert_UVA10816"; //*
+const string CPPfile = "aWalkThroughTheForest_UVA10917"; //*
 //***************************************
 
 ifstream fin(CPPfile + ".cpp");

myCpps/aWalkThroughTheForest_UVA10917.cpp

@@ -0,0 +1,98 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+ifstream fin("aWalkThroughTheForest_UVA10917.in");
+ofstream fout("aWalkThroughTheForest_UVA10917.out");
+
+using ll = long long;
+const ll inf = LLONG_MAX / 2;
+
+struct segment
+{
+    ll u;
+    ll d;
+
+    bool operator < (const segment & temp) const
+    {
+        return d > temp.d;
+    }
+};
+segment _segment(ll u, ll d)
+{
+    segment temp{u, d}; return temp;
+}
+
+ll count(ll u, vector<ll> & dp, vector<ll> & dis, vector<vector<ll>> & g)
+{
+    if (u == 2)
+    {
+        return 1;
+    }
+    else if (dp[u] != -1)
+    {
+        return dp[u];
+    }
+    else
+    {
+        ll ans = 0;
+
+        ll size = g[u].size();
+        for (ll i = 0; i <= size - 1; ++i)
+        {
+            ll v = g[u][i];
+
+            if (dis[v] < dis[u])
+            {
+                ans += count(v, dp, dis, g);
+            }
+        }
+
+        dp[u] = ans;
+        return ans;
+    }
+}
+
+int main()
+{
+    while (true)
+    {
+        ll n = 0; fin >> n;
+        if (n == 0) break;
+
+        ll m; fin >> m;
+
+        vector<vector<ll>> a(n + 1, vector<ll>(n + 1, inf)),
+                           g(n + 1);
+        for (ll c = 1; c <= m; ++c)
+        {
+            ll u, v, d; fin >> u >> v >> d;
+
+            a[u][v] = d; a[v][u] = a[u][v];
+            g[u].push_back(v); g[v].push_back(u);
+        }
+
+        vector<ll> dis(n + 1, inf);
+        priority_queue<segment> pq; pq.push(_segment(2, 0));
+        while (pq.empty() == false)
+        {
+            segment now = pq.top(); pq.pop();
+
+            if (now.d >= dis[now.u]) continue;
+            dis[now.u] = now.d;
+
+            ll size = g[now.u].size();
+            for (ll i = 0; i <= size - 1; ++i)
+            {
+                ll v = g[now.u][i];
+
+                pq.push(_segment(v, now.d + a[now.u][v]));
+            }
+        }
+
+        vector<ll> dp(n + 1, -1);
+        fout << count(1, dp, dis, g) << '\n';
+    }
+
+    return 0;
+}