# 查找数组中最接近的数字 > 原文： [https://www.geeksforgeeks.org/find-closest-number-array/](https://www.geeksforgeeks.org/find-closest-number-array/) 给定一个排序的整数数组。 我们需要找到最接近给定数字的值。 数组可能包含重复值和负数。 **示例**： ``` Input : arr[] = {1, 2, 4, 5, 6, 6, 8, 9} Target number = 11 Output : 9 9 is closest to 11 in given array Input :arr[] = {2, 5, 6, 7, 8, 8, 9}; Target number = 4 Output : 5 ``` **简单解决方案**是遍历给定数组，并跟踪每个元素与当前元素的绝对差。 最后返回具有最小绝对值差的元素。 一种有效的**解决方案**是使用[二分搜索](https://www.geeksforgeeks.org/binary-search/)。 ## C++ ```cpp // CPP program to find element // closet to given target. #include <bits/stdc++.h> using namespace std; int getClosest(int, int, int); // Returns element closest to target in arr[] int findClosest(int arr[], int n, int target) {     // Corner cases     if (target <= arr[0])         return arr[0];     if (target >= arr[n - 1])         return arr[n - 1];     // Doing binary search     int i = 0, j = n, mid = 0;     while (i < j) {         mid = (i + j) / 2;         if (arr[mid] == target)             return arr[mid];         /* If target is less than array element,             then search in left */         if (target < arr[mid]) {             // If target is greater than previous             // to mid, return closest of two             if (mid > 0 && target > arr[mid - 1])                 return getClosest(arr[mid - 1],                                   arr[mid], target);             /* Repeat for left half */             j = mid;         }         // If target is greater than mid         else {             if (mid < n - 1 && target < arr[mid + 1])                 return getClosest(arr[mid],                                   arr[mid + 1], target);             // update i             i = mid + 1;          }     }     // Only single element left after search     return arr[mid]; } // Method to compare which one is the more close. // We find the closest by taking the difference // between the target and both values. It assumes // that val2 is greater than val1 and target lies // between these two. int getClosest(int val1, int val2,                int target) {     if (target - val1 >= val2 - target)         return val2;     else         return val1; } // Driver code int main() {     int arr[] = { 1, 2, 4, 5, 6, 6, 8, 9 };     int n = sizeof(arr) / sizeof(arr[0]);     int target = 11;     cout << (findClosest(arr, n, target)); } // This code is contributed bu Smitha Dinesh Semwal ```