chore: added comments and changed variable name in hard day 5 solution

hard/day_5/solution.cpp

@@ -1,49 +1,55 @@
-//Write your code here
-// LUOGU_RID: 147799314
-#include <bits/stdc++.h>
+#include <bits/stdc++.h> // Include necessary header files
 using namespace std;
-typedef long long ll;
+typedef long long ll; // Define a shorthand for long long
 
-const int MAXN = 5e5 + 5;
+const int MAXN = 5e5 + 5; // Define maximum array size
 
-ll a[MAXN], dif[MAXN];
-map<int, ll> mp;
-int l_[MAXN], r_[MAXN]; ll x_[MAXN];
+ll initialArray[MAXN], differences[MAXN]; // Declare arrays for storing initial values and differences
+map<int, ll> valueChanges; // Declare a map to store the changes in values
+int queryLeft[MAXN], queryRight[MAXN]; ll queryValue[MAXN]; // Arrays to store left, right, and value changes for queries
 
-int main() { ios::sync_with_stdio(0); cin.tie(0);
-    int t; cin >> t; while (t--) {
-        int n; cin >> n;
-        for (int i = 1; i <= n; i++)
-            cin >> a[i];
-        int ans = 0;
-        int q; cin >> q; for (int i = 1; i <= q; i++) {
-            int l, r; ll x; cin >> l >> r >> x; l_[i] = l; r_[i] = r, x_[i] = x;
-            mp[l] += x;
-            if (r+1 <= n)
-                mp[r+1] -= x;
-            while (!mp.empty() && mp.begin()->second == 0)
-                mp.erase(mp.begin());
-            if (!mp.empty() && mp.begin()->second < 0) {
-                ans = i;
-                mp.clear();
+int main() { 
+    ios::sync_with_stdio(0); cin.tie(0); // Fast I/O
+
+    int t; cin >> t; // Input number of test cases
+    while (t--) { // Iterate over each test case
+        int n; cin >> n; // Input array size
+        for (int i = 1; i <= n; i++) // Input the initial array
+            cin >> initialArray[i];
+        int ans = 0; // Initialize the answer variable
+
+        int q; cin >> q; // Input number of queries
+        for (int i = 1; i <= q; i++) { // Loop over each query
+            int left, right; ll value; cin >> left >> right >> value; // Input query parameters
+            queryLeft[i] = left; queryRight[i] = right, queryValue[i] = value; // Store query parameters
+            valueChanges[left] += value; // Update the map with the value change
+            if (right + 1 <= n)
+                valueChanges[right + 1] -= value; // Adjust for the end of the range
+            while (!valueChanges.empty() && valueChanges.begin()->second == 0) // Remove zero values from the map
+                valueChanges.erase(valueChanges.begin());
+            if (!valueChanges.empty() && valueChanges.begin()->second < 0) { // If there's a negative value in the map
+                ans = i; // Update the answer with the current query index
+                valueChanges.clear(); // Clear the map
             }
         }
-        for (int i = 1; i <= ans; i++) {
-            int l = l_[i], r = r_[i]; ll x = x_[i];
-            dif[l] += x;
-            if (r+1 <= n)
-                dif[r+1] -= x;
+
+        for (int i = 1; i <= ans; i++) { // Process queries up to the answer
+            int left = queryLeft[i], right = queryRight[i]; ll value = queryValue[i]; // Retrieve query parameters
+            differences[left] += value; // Update difference array at start index
+            if (right + 1 <= n)
+                differences[right + 1] -= value; // Adjust difference array at end index
         }
-        for (int i = 1; i <= n; i++) {
-            dif[i] += dif[i-1];
-            a[i] += dif[i];
-            cout << a[i] << " \n"[i == n];
+
+        for (int i = 1; i <= n; i++) { // Apply differences to the array
+            differences[i] += differences[i - 1]; // Accumulate differences
+            initialArray[i] += differences[i]; // Update array value
+            cout << initialArray[i] << " \n"[i == n]; // Output array value
         }
 
-        // init
+        // Initialize arrays and map for the next test case
         for (int i = 1; i <= n; i++)
-            dif[i] = 0;
-        mp.clear();
+            differences[i] = 0;
+        valueChanges.clear();
     }
-    return 0;
+    return 0; // End of program
 }