使用C++语言进行编写

好的，下面是使用C++语言实现的代码：

#include <iostream>
#include <cmath>
#include <limits>

using namespace std;

bool is_prime(int n) {
    if (n < 2) {
        return false;
    }
    for (int i = 2; i <= sqrt(n); i++) {
        if (n % i == 0) {
            return false;
        }
    }
    return true;
}

void find_adjacent_primes(int L, int U) {
    int min_gap = numeric_limits<int>::max();
    int min_sum = numeric_limits<int>::max();
    int max_gap = -1;
    int max_sum = -1;
    int prev_prime = 0;
    for (int i = L; i <= U; i++) {
        if (is_prime(i)) {
            if (prev_prime != 0) {
                int gap = i - prev_prime;
                if (gap < min_gap) {
                    min_gap = gap;
                    min_sum = prev_prime + i;
                    cout << "The closest adjacent primes are " << prev_prime << " and " << i << ", with a gap of " << gap << "." << endl;
                } else if (gap == min_gap && prev_prime + i < min_sum) {
                    min_sum = prev_prime + i;
                    cout << "The closest adjacent primes are " << prev_prime << " and " << i << ", with a gap of " << gap << "." << endl;
                }
                if (gap > max_gap) {
                    max_gap = gap;
                    max_sum = prev_prime + i;
                    cout << "The farthest adjacent primes are " << prev_prime << " and " << i << ", with a gap of " << gap << "." << endl;
                } else if (gap == max_gap && prev_prime + i < max_sum) {
                    max_sum = prev_prime + i;
                    cout << "The farthest adjacent primes are " << prev_prime << " and " << i << ", with a gap of " << gap << "." << endl;
                }
            }
            prev_prime = i;
        }
    }
    if (min_gap == numeric_limits<int>::max()) {
        cout << "There are no adjacent primes in the given range." << endl;
    }
}

int main() {
    int L = 1;
    int U = 100;
    find_adjacent_primes(L, U);
    return 0;
}

这个程序的输出结果和之前Python版的程序一样。你可以根据需要修改L和U的值来测试不同的区间。