Solved problem 84D from codeforces

Author: AliOsm

CodeForces/84D. Doctor.cpp

@@ -0,0 +1,80 @@
+/*
+  Idea:
+    - We can reduce `k` if we try to remove animals from the smallest number of
+      examinations to the biggest.
+    - Then we can reduce `k` even more, we know that in the current state we
+      cannot remove any animal, but we can remove some examinations from the
+      animals by divide the remaining `k` by the remaining animals.
+    - Finally, the remaining `k` will be less than 10^5, so we can brute force
+      it.
+*/
+
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int const N = 1e5 + 10;
+int n, a[N];
+long long k, to, tt;
+vector<int> v;
+map<int, int> mp;
+queue<pair<int, int> > q;
+
+int main() {
+  scanf("%d %lld", &n, &k);
+  for(int i = 0; i < n; ++i) {
+    scanf("%d", a + i);
+    v.push_back(a[i]);
+    ++mp[a[i]];
+    to += a[i];
+  }
+
+  if(to < k) {
+    puts("-1");
+    return 0;
+  }
+
+  sort(v.begin(), v.end());
+  v.resize(unique(v.begin(), v.end()) - v.begin());
+
+  int cnt = n;
+  for(int i = 0, prv = 0; i < v.size(); ++i) {
+    if(k >= 1ll * (v[i] - prv) * cnt) {
+      k -= 1ll * (v[i] - prv) * cnt;
+      tt += (v[i] - prv);
+      cnt -= mp[v[i]];
+    } else
+      break;
+
+    prv = v[i];
+  }
+
+  for(int i = 0; i < n; ++i)
+    a[i] -= tt, a[i] = max(0, a[i]);
+
+  if(cnt == 0)
+    return 0;
+
+  int rem = k / cnt;
+  k -= 1ll * rem * cnt;
+
+  for(int i = 0; i < n; ++i)
+    if(a[i] > 0)
+      a[i] -= rem, q.push({a[i], i + 1});
+
+  for(int i = 0; i < k; ++i) {
+    pair<int, int> p = q.front();
+    q.pop();
+    if(--p.first == 0)
+      continue;
+    q.push(p);
+  }
+
+  while(!q.empty()) {
+    printf("%d ", q.front().second);
+    q.pop();
+  }
+  puts("");
+
+  return 0;
+}

CodeForces/README.md

@@ -45,6 +45,7 @@
 - [75D. Big Maximum Sum](http://codeforces.com/contest/75/problem/D)
 - [80A. Panoramix's Prediction](http://codeforces.com/problemset/problem/80/A)
 - [81A. Plug-in](http://codeforces.com/contest/81/problem/A)
+- [84D. Doctor](http://codeforces.com/contest/84/problem/D)
 - [94D. End of Exams](http://codeforces.com/contest/94/problem/D)
 - [96A. Football](http://codeforces.com/problemset/problem/96/A)
 - [96B. Lucky Numbers (easy)](http://codeforces.com/problemset/problem/96/B)