{"id":998,"date":"2024-10-15T13:32:21","date_gmt":"2024-10-15T08:02:21","guid":{"rendered":"https:\/\/codexplained.in\/?p=998"},"modified":"2025-11-24T15:41:21","modified_gmt":"2025-11-24T10:11:21","slug":"in-second-largest-element-in-an-array","status":"publish","type":"post","link":"https:\/\/codexplained.in\/?p=998","title":{"rendered":"In Second Largest Element In An Array"},"content":{"rendered":"
\n#include <stdio.h>\n#include <limits.h>\n\nint findSecondLargest(int arr[], int n) {\n    if (n < 2) {\n        return -1; \/\/ Not enough elements\n    }\n\n    int first = INT_MIN, second = INT_MIN;\n\n    for (int i = 0; i < n; i++) {\n        if (arr[i] > first) {\n            second = first;\n            first = arr[i];\n        } else if (arr[i] > second && arr[i] < first) {\n            second = arr[i];\n        }\n    }\n\n    return (second == INT_MIN) ? -1 : second; \/\/ Return -1 if second largest doesn't exist\n}\n\nint main() {\n    int array[] = {12, 35, 1, 10, 34, 1};\n    int n = sizeof(array) \/ sizeof(array[0]);\n    int result = findSecondLargest(array, n);\n    \n    if (result != -1) {\n        printf("The second largest element is: %d\\n", result);\n    } else {\n        printf("There is no second largest element.\\n");\n    }\n\n    return 0;\n}\n\n<\/pre><\/div>\n\n\n
Explanation<\/h3>\n\n\n\n
    \n
  1. Include Headers<\/strong>: The program starts by including the standard input-output header (<stdio.h><\/code>) and the limits header (<limits.h><\/code>) for defining constants.<\/li>\n\n\n\n
  2. Function Definition<\/strong>: The function findSecondLargest<\/code> takes an array and its size as arguments. It returns the second largest element or -1<\/code> if it doesn’t exist.<\/li>\n\n\n\n
  3. Edge Case Check<\/strong>: The function first checks if the size of the array is less than 2. If so, it returns -1<\/code>, indicating there aren’t enough elements.<\/li>\n\n\n\n
  4. Initialization<\/strong>: Two variables, first<\/code> and second<\/code>, are initialized to the smallest possible integer value (INT_MIN<\/code>). This allows for comparison with any number in the array.<\/li>\n\n\n\n
  5. Iteration<\/strong>: The function loops through the array:\n
      \n
    • If the current element is greater than first<\/code>, it updates second<\/code> to be first<\/code> and sets first<\/code> to the current element.<\/li>\n\n\n\n
    • If the current element is not larger than first<\/code> but is larger than second<\/code>, it updates second<\/code>.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
    • Return Value<\/strong>: After the loop, if second<\/code> is still INT_MIN<\/code>, it means there was no valid second largest element, and the function returns -1<\/code>. Otherwise, it returns the value of second<\/code>.<\/li>\n<\/ol>\n\n\n\n
      Output<\/h3>\n\n\n\n
      For the input array {12, 35, 1, 10, 34, 1}<\/code>, the output will be:<\/p>\n\n\n\n
      csharpCopy codeThe second largest element is: 34\n<\/code><\/pre>\n\n\n\n
      This implementation efficiently finds the second largest element in a single pass through the array, achieving O(n) time complexity.<\/p>\n