程序的第8、11行，改为 m-1、n-1 也不会出错。（ ）

#include <bits/stdc++.h>
using namespace std;
vector<int> nums1, nums2;
int m, n, t;
int f(int k) {
    int index1 = 0, index2 = 0;
    while (true) {
        if (index1 == m) {
            return nums2[index2 + k - 1];
        }
        if (index2 == n) {
            return nums1[index1 + k - 1];
        }
        if (k == 1) {
            return min(nums1[index1], nums2[index2]);
        }
        int newIndex1 = min(index1 + k / 2 - 1, m - 1);
        int newIndex2 = min(index2 + k / 2 - 1, n - 1);
        int pivot1 = nums1[newIndex1];
        int pivot2 = nums2[newIndex2];
        if (pivot1 <= pivot2) {
            k -= newIndex1 - index1 + 1;
            index1 = newIndex1 + 1;
        } else {
            k -= newIndex2 - index2 + 1;
            index2 = newIndex2 + 1;
        }
    }
}

int main(){
    cin >> m >> n;
    for (int i = 0; i <= m-1; i++){
        cin >> t;
        nums1.push_back(t);
    }
    for (int i = 0; i <= n-1; i++){
        cin >> t;
        nums2.push_back(t);
    }
    int totalLength = nums1.size() + nums2.size();
    if (totalLength & 1) {
        cout << f((totalLength + 1) / 2);
    } else {
        cout << (f(totalLength / 2) + f(totalLength / 2 + 1)) / 2.0;
    }
    return 0;
}