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  1. #include <iostream>
  2. #include <vector>
  3. #include <climits>
  4. using namespace std;
  5.  
  6. // Function to calculate the smallest maximum element after skipping one update
  7. long long skipUpdate(int N, int Q, vector<int>& A, vector<vector<int>>& updates) {
  8.     // Step 1: Create a difference array for all updates
  9.     vector<long long> diff(N + 2, 0);
  10.  
  11.     // Apply all updates to the difference array
  12.     for (const auto& update : updates) {
  13.         int L = update[0];
  14.         int R = update[1];
  15.         int X = update[2];
  16.         diff[L] += X;
  17.         if (R + 1 <= N) {
  18.             diff[R + 1] -= X;
  19.         }
  20.     }
  21.  
  22.     // Step 2: Compute the fully updated array
  23.     vector<long long> fullArray(N + 1, 0);
  24.     fullArray[1] = A[0] + diff[1];
  25.     for (int i = 2; i <= N; ++i) {
  26.         diff[i] += diff[i - 1];
  27.         fullArray[i] = A[i - 1] + diff[i];
  28.     }
  29.  
  30.     // Step 3: Calculate prefix and suffix maximums
  31.     vector<long long> prefixMax(N + 2, LLONG_MIN);
  32.     vector<long long> suffixMax(N + 2, LLONG_MIN);
  33.  
  34.     // Prefix maximums: max up to index i
  35.     for (int i = 1; i <= N; ++i) {
  36.         prefixMax[i] = max(prefixMax[i - 1], fullArray[i]);
  37.     }
  38.  
  39.     // Suffix maximums: max from index i to end
  40.     for (int i = N; i >= 1; --i) {
  41.         suffixMax[i] = max(suffixMax[i + 1], fullArray[i]);
  42.     }
  43.  
  44.     // Step 4: Iterate through each update and calculate the result
  45.     long long minMaxValue = LLONG_MAX;
  46.  
  47.     for (const auto& update : updates) {
  48.         int L = update[0];
  49.         int R = update[1];
  50.         int X = update[2];
  51.  
  52.         // Calculate the maximum without applying this update
  53.         long long currentMax = LLONG_MIN;
  54.  
  55.         // Left part before L
  56.         if (L > 1) {
  57.             currentMax = max(currentMax, prefixMax[L - 1]);
  58.         }
  59.  
  60.         // Right part after R
  61.         if (R < N) {
  62.             currentMax = max(currentMax, suffixMax[R + 1]);
  63.         }
  64.  
  65.         minMaxValue = min(minMaxValue, currentMax);
  66.     }
  67.  
  68.     return minMaxValue;
  69. }
  70.  
  71. int main() {
  72.     int T;
  73.     cin >> T;
  74.  
  75.     while (T--) {
  76.         int N, Q;
  77.         cin >> N >> Q;
  78.  
  79.         vector<int> A(N);
  80.         for (int i = 0; i < N; ++i) {
  81.             cin >> A[i];
  82.         }
  83.  
  84.         vector<vector<int>> updates(Q, vector<int>(3));
  85.         for (int i = 0; i < Q; ++i) {
  86.             cin >> updates[i][0] >> updates[i][1] >> updates[i][2];
  87.         }
  88.  
  89.         cout << skipUpdate(N, Q, A, updates) << endl;
  90.     }
  91.  
  92.     return 0;
  93. }
  94.  
Success #stdin #stdout 0s 5284KB
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https://ideone.com/BahNFQ
language:
C++14 (gcc 8.3)
created:
10 days ago
visibility:
public

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