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  1. /*Write a program to take an integer array nums of size n, and print the majority element. The majority element is
  2. the element that appears strictly more than ⌊n / 2⌋ times. Print -1 if no such element exists. Note: Majority
  3. Element is not necessarily the element that is present most number of times.*/
  4. #include <stdio.h>
  5.  
  6. int main() {
  7.     int n;
  8.     scanf("%d", &n);
  9.  
  10.     int nums[n];
  11.     for (int i = 0; i < n; i++) scanf("%d", &nums[i]);
  12.  
  13.     // Boyer–Moore Voting
  14.     int candidate = 0, count = 0;
  15.     for (int i = 0; i < n; i++) {
  16.         if (count == 0) candidate = nums[i];
  17.         count += (nums[i] == candidate) ? 1 : -1;
  18.     }
  19.  
  20.     // Verify candidate is actually majority
  21.     count = 0;
  22.     for (int i = 0; i < n; i++)
  23.         if (nums[i] == candidate) count++;
  24.  
  25.     if (count > n / 2) printf("%d", candidate);
  26.     else printf("-1");
  27.  
  28.     return 0;
  29. }
  30.  
Success #stdin #stdout 0s 5320KB
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https://ideone.com/GSaJx7
language:
C (gcc 8.3)
created:
1 hour ago
visibility:
public

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