比较两个INT64_T给出不匹配/匹配错误

Question

#include <iostream>
#include <vector>
#include <math.h>
using std::cout;
using std::cin;
using std::endl;
using std::vector;
int main()
{

    int64_t default_min = 1'000'000'000;
    int64_t n;
    cin >> n;
    vector<int64_t> city(n);
    vector<int64_t> min(n, default_min);
    vector<int64_t> max(n, 0);

    for (auto& i : city) 
    {
        cin >> i;
    }
    for (int i = 0; i < n; i++) {//max
        if (i != 0 || i != n - 1) {
            if (signed int(city[i] - city[i-1]) >= signed int(city[i+1] - city[i]))
            {
                max[i] = abs(city[i] - city[i - 1]);
                min[i] = abs(city[i] - city[i + 1]);
            }
            else {
                min[i] = abs(city[i] - city[i - 1]);
                max[i] = abs(city[i] - city[i + 1]);
            }
        }
        else if (i == 0) {
            min[i] = city[1] - city[0];
            max[i] = city[n-1] - city[0];
        }
        else if (i == n-1) {
            min[i] = city[n-1] - city[n-2];
            max[i] = max[0];
        }
    }
    for (int i=0;i<n;i++)
    {
        cout << min[i] << " " << max[i]<<endl;
    }
    
}

我尝试在比较行中将其转换为无符号或两侧有符号，但它不起作用，我达到了这一点，因为到目前为止我找不到其他方法来轻松比较向量内的值..所以有没有办法通过以更有效的方式转换或比较向量来避免不匹配/匹配错误