# 整個數組中最小的較大元素 > 原文： [https://www.geeksforgeeks.org/smallest-greater-elements-in-whole-array/](https://www.geeksforgeeks.org/smallest-greater-elements-in-whole-array/) 給定一個長度為`n`的數組，我們需要為給定數組中的每個元素計算下一個更大的元素。 如果下一個更大的元素在給定數組中不可用，那么我們需要在該索引位置填充`_`。 **示例**： ``` Input : 6 3 9 8 10 2 1 15 7 Output : 7 6 10 9 15 3 2 _ 8 Here every element of array has next greater element but at index 7, 15 is the greatest element of given array and no other element is greater from 15 so at the index of 15 we fill with '_' . Input : 13 6 7 12 Output : _ 7 12 13 Here, at index 0, 13 is the greatest value in given array and no other array element is greater from 13 so at index 0 we fill '_'. ``` **簡單解決方案**是使用兩個嵌套的循環。 外循環一個接一個地選擇所有元素，內循環通過從頭到尾線性搜索找到下一個更大的元素。 ## C++ ```cpp // Simple CPP program to find smallest // greater element in whole array for? // every element. #include <bits/stdc++.h> using namespace std; void smallestGreater(int arr[], int n) { ????for (int i = 0; i < n; i++) { ????????// Find the closest greater element? ????????// for arr[j] in the entire array. ????????int diff = INT_MAX, closest = -1; ????????for (int j = 0; j < n; j++) { ????????????if ( arr[i] < arr[j] &&? ?????????????????arr[j] - arr[i] < diff) ????????????{ ????????????????diff = arr[j] - arr[i]; ????????????????closest = j;???????????? ????????????} ????????} ????????// Check if arr[i] is largest ????????(closest == -1)?? cout << "_ "? :? ??????????????cout << arr[closest] << " "; ?????} } // Driver code int main() { ????int ar[] = { 6, 3, 9, 8, 10, 2, 1, 15, 7 }; ????int n = sizeof(ar) / sizeof(ar[0]); ????smallestGreater(ar, n); ????return 0; } ```