頭文件（持續迭代）

#pragma GCC optimize(2)
#pragma GCC optimize(3)
#include <bits/stdc++.h>
#define pii pair <int, int>
#define mp(a, b) make_pair(a, b)
#define IO std::ios::sync_with_stdio(false)
#define ll long long
#define INF (int)1e18
using namespace std;

inline int read() {
  int x = 0, neg = 1; char op = getchar();
  while (!isdigit(op)) { if (op == '-') neg = -1; op = getchar(); }
  while (isdigit(op)) { x = 10 * x + op - '0'; op = getchar(); }
  return neg * x;
}
inline void print(int x) {
  if (x < 0) { putchar('-'); x = -x; }
  if (x >= 10) print(x / 10);
  putchar(x % 10 + '0');
}

部分說明

#define pii pair <int, int> // <string,int>

#define INF (int)1e18  //2147483647
//隨題目可更改爲
#define INF (long long)1e18  //1000000000000000000

//快讀 快輸
int -> __int128
//根據題目是否含階層、次冪等大數運算決定