双指针（对撞指针）模版题

#include <iostream>

using namespace std;

int main(void) {
  int n, m, x;
  cin >> n >> m >> x;
  int a[n], b[m];
  for (int i = 0; i < n; ++i) cin >> a[i];
  for (int i = 0; i < m; ++i) cin >> b[i];

  int i = 0, j = m - 1;
  while (i < n && j >= 0) {
    int s = a[i] + b[j];
    if (s == x) return printf("%d %d\n", i, j), 0;
    if (s < x) ++i;
    else --j;
  }

  return 0;
}