Problem p00830 (C++) — buggy submission, verdict: Runtime Error

#include <algorithm>
#include <iomanip>
#include <iostream>
#include <map>
#include <math.h>
#include <numeric>
#include <set>
#include <sstream>
#include <stdio.h>
#include <string.h>
#include <string>
#include <vector>

#define rep(i, j) for (int i = 0; i < j; i++)
#define all(i) i.begin(), i.end()
#define clr(n) memset(n, 0, sizeof(n))
#define ll long long

using namespace std;
#define double long double

vector<string> split(string s) {
  vector<string> r;
  string n;
  s += '/';
  rep(i, s.size()) {
    if (s[i] == '/') {
      r.push_back(n);
      n.clear();
    } else {
      n.push_back(s[i]);
    }
  }
  if (r.back().size() == 0) {
    r[r.size() - 1] = "index.html";
  }
  return r;
}

#include <functional>

int main() {
  int n, m;
  while (cin >> n >> m && n) {
    vector<map<string, int>> mp;
    vector<map<string, int>> fs;
    vector<int> p;
    int count = 0;

    function<void(int, vector<string>)> make = [&](int now, vector<string> vs) {
      string s = vs[0];
      if (vs.size() == 1) {
        fs[now][s] = count++;
        return;
      }
      if (mp[now].count(s) == false) {
        mp[now][s] = mp.size();
        mp.push_back(map<string, int>());
        fs.push_back(map<string, int>());
        p.push_back(now);
      }
      vs.erase(vs.begin());
      make(mp[now][s], vs);
    };

    function<int(int, vector<string>, int)> search =
        [&](int now, vector<string> vs, int f) {
          if (vs.size() == 0)
            return -1;
          if (vs[0] == "..") {
            vs.erase(vs.begin());
            if (p[now] == 0)
              return -1;
            return search(p[now], vs, f);
          }
          if (vs[0] == ".") {
            vs.erase(vs.begin());
            return search(now, vs, f);
          }
          string s = vs[0];
          if (vs.size() == 1) {
            if (fs[now].count(s)) {
              return fs[now][s];
            } else {
              return -1;
            }
          }
          if (mp[now].count(s) == false) {
            return -1;
          }
          vs.erase(vs.begin());
          return search(mp[now][s], vs, f);
        };

    mp.push_back(map<string, int>());
    fs.push_back(map<string, int>());
    p.push_back(-1);

    rep(i, n) {
      string s;
      cin >> s;
      auto vs = split(s);
      make(0, vs);
    }
    rep(i, m) {
      string a, b;
      cin >> a >> b;
      int ta = search(0, split(a), 0);
      int tb = search(0, split(b), 0);
      if (ta == -1) {
        a += "/index.html";
        ta = search(0, split(a), 0);
      }
      if (tb == -1) {
        b += "/index.html";
        tb = search(0, split(b), 0);
      }
      if (ta == -1 || tb == -1) {
        cout << "not found" << endl;
        continue;
      }
      if (ta == tb) {
        cout << "yes" << endl;
        continue;
      }
      cout << "no" << endl;
    }
  }

  return 0;
}

Error: 0

Fixed submission:

#include <algorithm>
#include <iomanip>
#include <iostream>
#include <map>
#include <math.h>
#include <numeric>
#include <set>
#include <sstream>
#include <stdio.h>
#include <string.h>
#include <string>
#include <vector>

#define rep(i, j) for (int i = 0; i < j; i++)
#define all(i) i.begin(), i.end()
#define clr(n) memset(n, 0, sizeof(n))
#define ll long long

using namespace std;
#define double long double

vector<string> split(string s) {
  vector<string> r;
  string n;
  s += '/';
  rep(i, s.size()) {
    if (s[i] == '/') {
      r.push_back(n);
      n.clear();
    } else {
      n.push_back(s[i]);
    }
  }
  if (r.back().size() == 0) {
    r[r.size() - 1] = "index.html";
  }
  return r;
}

#include <functional>

int main() {
  int n, m;
  while (cin >> n >> m && n) {
    vector<map<string, int>> mp;
    vector<map<string, int>> fs;
    vector<int> p;
    int count = 0;

    function<void(int, vector<string>)> make = [&](int now, vector<string> vs) {
      string s = vs[0];
      if (vs.size() == 1) {
        fs[now][s] = count++;
        return;
      }
      if (mp[now].count(s) == false) {
        mp[now][s] = mp.size();
        mp.push_back(map<string, int>());
        fs.push_back(map<string, int>());
        p.push_back(now);
      }
      vs.erase(vs.begin());
      make(mp[now][s], vs);
    };

    function<int(int, vector<string>, int)> search =
        [&](int now, vector<string> vs, int f) {
          if (vs[0] == "..") {
            vs.erase(vs.begin());
            if (p[now] == 0)
              return -1;
            return search(p[now], vs, f);
          }
          if (vs[0] == ".") {
            vs.erase(vs.begin());
            return search(now, vs, f);
          }
          string s = vs[0];
          if (vs.size() == 1) {
            if (fs[now].count(s)) {
              return fs[now][s];
            } else {
              return -1;
            }
          }
          if (mp[now].count(s) == false) {
            return -1;
          }
          vs.erase(vs.begin());
          return search(mp[now][s], vs, f);
        };

    mp.push_back(map<string, int>());
    fs.push_back(map<string, int>());
    p.push_back(-1);

    rep(i, n) {
      string s;
      cin >> s;
      auto vs = split(s);
      make(0, vs);
    }
    rep(i, m) {
      string a, b;
      cin >> a >> b;
      int ta = search(0, split(a), 0);
      int tb = search(0, split(b), 0);
      if (ta == -1) {
        a += "/index.html";
        ta = search(0, split(a), 0);
      }
      if (tb == -1) {
        b += "/index.html";
        tb = search(0, split(b), 0);
      }
      if (ta == -1 || tb == -1) {
        cout << "not found" << endl;
        continue;
      }
      if (ta == tb) {
        cout << "yes" << endl;
        continue;
      }
      cout << "no" << endl;
    }
  }

  return 0;
}