No commit message

myCpps/fireStation_UVA10278.cpp

@@ -0,0 +1,109 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+ifstream fin("fireStation_UVA10278.in");
+ofstream fout("fireStation_UVA10278.out");
+
+const int inf = INT_MAX / 2;
+
+int main()
+{
+    int testCase; fin >> testCase;
+    for (int t = 1; t <= testCase; ++t)
+    {
+        if (t > 1) fout << '\n';
+
+        int fn, in; fin >> fn >> in;
+
+        vector<bool> isStation(in + 1, false);
+        vector<vector<int>> d(in + 1, vector<int>(in + 1, inf)),
+                            g(in + 1);
+
+        for (int c = 1; c <= fn; ++c)
+        {
+            int u; fin >> u;
+            isStation[u] = true;
+        }
+
+        string tempIn = "";
+        getline(fin, tempIn);
+
+        while (true)
+        {
+            getline(fin, tempIn);
+            if (tempIn == "") break;
+
+            istringstream inTempIn(tempIn);
+
+            int u, v, l; inTempIn >> u >> v >> l;
+
+            d[u][v] = min(d[u][v], l); d[v][u] = d[u][v];
+            g[u].push_back(v); g[v].push_back(u);
+        }
+
+
+        if (in == 1)
+        {
+            fout << "1\n";
+            continue;
+        }
+
+
+        for (int i = 1; i <= in; ++i)
+        {
+            d[i][i] = 0;
+        }
+
+        for (int k = 1; k <= in; ++k)
+        {
+            for (int u = 1; u <= in; ++u)
+            {
+                for (int v = 1; v <= in; ++v)
+                {
+                    d[u][v] = min(d[u][v], d[u][k] + d[k][v]);
+                }
+            }
+        }
+
+        vector<int> minDis(in + 1, inf);
+        for (int u = 1; u <= in; ++u)
+        {
+            if (isStation[u] == true)
+            {
+                for (int v = 1; v <= in; ++v)
+                {
+                    minDis[v] = min(minDis[v], d[u][v]);
+                }
+            }
+        }
+
+        int nowMaxMinDis = 0;
+        for (int i = 1; i <= in; ++i)
+        {
+            nowMaxMinDis = max(nowMaxMinDis, minDis[i]);
+        }
+
+        int bestMaxMinDis = nowMaxMinDis, bestI = 0;
+        for (int u = 1; u <= in; ++u)
+        {
+            if (isStation[u] == true) continue;
+
+            int tempMaxMinDis = -inf;
+            for (int v = 1; v <= in; ++v)
+            {
+                tempMaxMinDis = max(tempMaxMinDis, min(d[u][v], minDis[v]));
+            }
+
+            if (tempMaxMinDis < bestMaxMinDis)
+            {
+                bestMaxMinDis = tempMaxMinDis;
+                bestI = u;
+            }
+        }
+
+        fout << max(bestI, 1) << '\n';
+    }
+
+    return 0;
+}