candies test set 1

google/roundC2020/candies/candies.cpp

@@ -0,0 +1,63 @@
+// https://codingcompetitions.withgoogle.com/kickstart/round/000000000019ff43/0000000000337b4d
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#define MAX_N 2e5
+#define ll long long
+
+vector<int> vals(MAX_N + 1);
+vector<ll> ps(MAX_N + 1), mps(MAX_N + 1);
+
+// TODO: solve whole problem with segtrees?
+
+int main()
+{
+  int T;
+  cin >> T;
+
+  int N, Q;
+  int mult;
+
+  ll ans;
+
+  char c;
+  int a, b;
+  for (int t = 1; t <= T; ++t)
+  {
+    cin >> N >> Q;
+    mult = 1;
+
+    ps[0] = 0, mps[0] = 0;
+    for (int i = 1; i <= N; ++i)
+    {
+      cin >> vals[i];
+      ps[i] = ps[i - 1] + mult * vals[i];
+      mps[i] = mps[i - 1] + mult * vals[i] * i;
+      mult *= -1;
+    }
+
+    ans = 0;
+    for (int q = 0; q < Q; ++q)
+    {
+      cin >> c >> a >> b;
+      mult = a % 2 == 0 ? -1 : 1;
+      if (c == 'Q')
+        ans += mult * ((mps[b] - mps[a - 1]) - (a - 1) * (ps[b] - ps[a - 1]));
+      else if (c == 'U')
+      {
+        vals[a] = b;
+        for (int i = a; i <= N; ++i)
+        {
+          ps[i] = ps[i - 1] + mult * vals[i];
+          mps[i] = mps[i - 1] + mult * vals[i] * i;
+          mult *= -1;
+        }
+      }
+    }
+
+    cout << "Case #" << t << ": " << ans << '\n';
+  }
+
+  return 0;
+}