Add 1838-frequency-of-the-most-frequent-element.c

c/1838-frequency-of-the-most-frequent-element.c

@@ -0,0 +1,34 @@
+int greater(const void *a, const void *b) {
+    return *(int*)a - *(int*)b;
+}
+
+int maxFrequency(int* nums, int numsSize, int k){
+    int left, right;
+    long sum = 0;
+    qsort(nums, numsSize, sizeof(int), greater);
+
+    //
+    // Exapmle;
+    // nums = [2, 3, 1, 4], k = 3
+    //
+    // After the array is sorted
+    // ------
+    // X X X O
+    // X X O O
+    // X O O O
+    // O O O O 
+    // ------
+    // 'O' represents the value of the array.
+    // 'X' represents the value added by each operation.
+    // Just need to find the longer interval where the number of 'X'
+    // is less than or equal to k.
+    //
+
+    for (right = 0, left = 0; right < numsSize; right++) {
+        sum += nums[right];
+        if ((long)(right - left + 1) * nums[right] - sum > k) {
+            sum -= nums[left++];
+        }
+    }
+    return right - left;
+}