Language: C++

#include <iostream>
#include <string>
#include <algorithm>
#include <ctime>
#include <functional>
#include <vector>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <cassert>
#include <bitset>
#include <list>
#include <cstdio>
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <math.h>
#include <cmath>
#include <tuple>
#include <cassert>

using namespace std;
using ll = long long;
using pii = pair<int, int>;
using ti = tuple<int, int, int>;

#define FOR(i,m,n) for(int (i)=(m); (i)<(n); (i)++)
#define REP(i,n) for(int (i))=0; (i)<(n); (i)++)
#define RFOR(i,n,m) for(int (i)=(n);i>=(m); (i)--)
#define RREP(i,n) for(int (i)=(n-1); (i)>=0; (i)--)
#define pb push_back
#define mp make_pair
#define debug(x) cerr << #x << ": " << x << endl
// #define int long long 

const double eps=1e-14;
const int mod = 1e9 + 7;
const int inf = 100100100;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};

struct mint 
{
  ll x;
  mint(ll x=0):x((x%mod+mod)%mod){}
  mint operator-() const { return mint(-x);}
  mint& operator+=(const mint a) {
    if ((x += a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator-=(const mint a) {
    if ((x += mod-a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this;}
  mint operator+(const mint a) const { return mint(*this) += a;}
  mint operator-(const mint a) const { return mint(*this) -= a;}
  mint operator*(const mint a) const { return mint(*this) *= a;}
  mint pow(ll t) const {
    if (!t) return 1;
    mint a = pow(t>>1);
    a *= a;
    if (t&1) a *= *this;
    return a;
  }
  mint inv() const { return pow(mod-2);}
  mint& operator/=(const mint a) { return *this *= a.inv();}
  mint operator/(const mint a) const { return mint(*this) /= a;}
};
istream& operator>>(istream& is, const mint& a) { return is >> a.x;}
ostream& operator<<(ostream& os, const mint& a) { return os << a.x;}

mint dp0[2005][2005];
mint dp1[2005][2005];

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, m;
    cin >> n >> m;
    vector<int> s(n+1), t(m+1);
    REP(i,n) cin >> s[i];
    REP(i,m) cin >> t[i];
    dp0[0][0] = 1;1
    REP(i,n+1) REP(j,m+1)
    {
        dp0[i+1][j] += dp0[i][j];
        dp1[i][j] += dp0[i][j];
        dp1[i][j+1] += dp1[i][j];
        if(s[i] == t[j]) dp0[i+1][j+1] += dp1[i][j];
    }
    mint ans = dp1[n][m];
    cout << ans.x << endl;
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:29:29: error: expected ';' before ')' token
   29 | #define REP(i,n) for(int (i))=0; (i)<(n); (i)++)
      |                             ^
a.cc:84:5: note: in expansion of macro 'REP'
   84 |     REP(i,n) cin >> s[i];
      |     ^~~
a.cc:29:29: error: expected primary-expression before ')' token
   29 | #define REP(i,n) for(int (i))=0; (i)<(n); (i)++)
      |                             ^
a.cc:84:5: note: in expansion of macro 'REP'
   84 |     REP(i,n) cin >> s[i];
      |     ^~~
a.cc:29:29: error: expected ';' before ')' token
   29 | #define REP(i,n) for(int (i))=0; (i)<(n); (i)++)
      |                             ^
a.cc:84:5: note: in expansion of macro 'REP'
   84 |     REP(i,n) cin >> s[i];
      |     ^~~
a.cc:29:30: error: expected primary-expression before '=' token
   29 | #define REP(i,n) for(int (i))=0; (i)<(n); (i)++)
      |                              ^
a.cc:84:5: note: in expansion of macro 'REP'
   84 |     REP(i,n) cin >> s[i];
      |     ^~~
a.cc:84:9: error: 'i' was not declared in this scope
   84 |     REP(i,n) cin >> s[i];
      |         ^
a.cc:29:35: note: in definition of macro 'REP'
   29 | #define REP(i,n) for(int (i))=0; (i)<(n); (i)++)
      |                                   ^
a.cc:29:29: error: expected ';' before ')' token
   29 | #define REP(i,n) for(int (i))=0; (i)<(n); (i)++)
      |                             ^
a.cc:85:5: note: in expansion of macro 'REP'
   85 |     REP(i,m) cin >> t[i];
      |     ^~~
a.cc:29:29: error: expected primary-expression before ')' token
   29 | #define REP(i,n) for(int (i))=0; (i)<(n); (i)++)
      |                             ^
a.cc:85:5: note: in expansion of macro 'REP'
   85 |     REP(i,m) cin >> t[i];
      |     ^~~
a.cc:29:29: error: expected ';' before ')' token
   29 | #define REP(i,n) for(int (i))=0; (i)<(n); (i)++)
      |                             ^
a.cc:85:5: note: in expansion of macro 'REP'
   85 |     REP(i,m) cin >> t[i];
      |     ^~~
a.cc:29:30: error: expected primary-expression before '=' token
   29 | #define REP(i,n) for(int (i))=0; (i)<(n); (i)++)
      |                              ^
a.cc:85:5: note: in expansion of macro 'REP'
   85 |     REP(i,m) cin >> t[i];
      |     ^~~
a.cc:86:20: error: expected ';' before 'for'
   86 |     dp0[0][0] = 1;1
      |                    ^
      |                    ;
a.cc:87:20: error: 'j' was not declared in this scope
   87 |     REP(i,n+1) REP(j,m+1)
      |                    ^
a.cc:29:35: note: in definition of macro 'REP'
   29 | #define REP(i,n) for(int (i))=0; (i)<(n); (i)++)
      |                                   ^