用的二分，好像也可以哎

`
using namespace std;
const int N = 100002;

int main() {
    int m, n, c;
    int arr1[N] = { 0 };
    int arr2[N] = { 0 };
    cin >> m >> n >> c;

    for (int i = 0; i < m; i++) {
        cin >> arr1[i];
    }

    for (int i = 0; i < n; i++) {
        cin >> arr2[i];
    }

    int i = 0;
    while (i < m && arr1[i] < c) {
        int l = 0, r = n - 1;
        int target = c - arr1[i];
        while (l <= r) {
            int mid = l + r >> 1;    //l   mid   r ;
            if (arr2[mid] > target) r = mid - 1;
            if (arr2[mid] < target) l = mid + 1;
            if (arr2[mid] == target) {
                cout << i << " " << mid << endl;
                break;
            }
        }
        i++;
    }

    return 0;
}`