Problem p02873 (C++)

Buggy submission (status: Runtime Error):
#pragma GCC optimize("O3")
#pragma GCC target("sse4")

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef pair<ld, ld> pd;
typedef pair<int, pi> pii;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

#define fax(i, a) for (int i = 0; i < (a); i++)
#define f0x(i, a, b) for (int i = (a); i < (b); i++)
#define f0xd(i, a, b) for (int i = (b)-1; i >= (a); i--)
#define faxd(i, a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto &a : x)
#define memeset memset

#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rsz resize

template <class T> void ckmin(T &a, T b) { a = min(a, b); }
template <class T> void ckmax(T &a, T b) { a = max(a, b); }

template <class T, int... Ns> struct BIT {
  T val = 0;
  void upd(T v) { val += v; }
  T query() { return val; }
};

template <class T, int N, int... Ns> struct BIT<T, N, Ns...> {
  BIT<T, Ns...> bit[N + 1];
  template <typename... Args> void upd(int pos, Args... args) {
    for (; pos <= N; pos += (pos & -pos))
      bit[pos].upd(args...);
  }
  template <typename... Args> T sum(int r, Args... args) {
    T res = 0;
    for (; r; r -= (r & -r))
      res += bit[r].query(args...);
    return res;
  }
  template <typename... Args> T query(int l, int r, Args... args) {
    return sum(r, args...) - sum(l - 1, args...);
  }
};

namespace input {
template <class T> void re(complex<T> &x);
template <class T1, class T2> void re(pair<T1, T2> &p);
template <class T> void re(vector<T> &a);
template <class T, size_t SZ> void re(array<T, SZ> &a);

template <class T> void re(T &x) { cin >> x; }
void re(double &x) {
  string t;
  re(t);
  x = stod(t);
}
void re(ld &x) {
  string t;
  re(t);
  x = stold(t);
}
template <class T, class... Ts> void re(T &t, Ts &...ts) {
  re(t);
  re(ts...);
}

template <class T> void re(complex<T> &x) {
  T a, b;
  re(a, b);
  x = cd(a, b);
}
template <class T1, class T2> void re(pair<T1, T2> &p) { re(p.f, p.s); }
template <class T> void re(vector<T> &a) { fax(i, sz(a)) re(a[i]); }
template <class T, size_t SZ> void re(array<T, SZ> &a) { fax(i, SZ) re(a[i]); }
} // namespace input

using namespace input;

namespace output {
void pr(int x) { cout << x; }
void pr(long x) { cout << x; }
void pr(ll x) { cout << x; }
void pr(unsigned x) { cout << x; }
void pr(unsigned long x) { cout << x; }
void pr(unsigned long long x) { cout << x; }
void pr(float x) { cout << x; }
void pr(double x) { cout << x; }
void pr(ld x) { cout << x; }
void pr(char x) { cout << x; }
void pr(const char *x) { cout << x; }
void pr(const string &x) { cout << x; }
void pr(bool x) { pr(x ? "true" : "false"); }

template <class T1, class T2> void pr(const pair<T1, T2> &x);
template <class T> void pr(const T &x);

template <class T, class... Ts> void pr(const T &t, const Ts &...ts) {
  pr(t);
  pr(ts...);
}
template <class T1, class T2> void pr(const pair<T1, T2> &x) {
  pr("{", x.f, ", ", x.s, "}");
}
template <class T> void pr(const T &x) {
  pr("{"); // const iterator needed for vector<bool>
  bool fst = 1;
  for (const auto &a : x)
    pr(!fst ? ", " : "", a), fst = 0;
  pr("}");
}

void ps() { pr("\n"); } // print w/ spaces
template <class T, class... Ts> void ps(const T &t, const Ts &...ts) {
  pr(t);
  if (sizeof...(ts))
    pr(" ");
  ps(ts...);
}

void pc() { pr("]\n"); } // debug w/ commas
template <class T, class... Ts> void pc(const T &t, const Ts &...ts) {
  pr(t);
  if (sizeof...(ts))
    pr(", ");
  pc(ts...);
}
#define dbg(x...) pr("[", #x, "] = ["), pc(x);
} // namespace output

using namespace output;

namespace io {
void setIn(string s) { freopen(s.c_str(), "r", stdin); }
void setOut(string s) { freopen(s.c_str(), "w", stdout); }
void setIO(string s = "") {
  ios_base::sync_with_stdio(0);
  cin.tie(0); // fast I/O
  if (sz(s)) {
    setIn(s + ".in"), setOut(s + ".out");
  } // for USACO
}
} // namespace io

using namespace io;

const int MOD = 1000000007; // 998244353
const ll INF = 1e18;
const int MX = 200005;
const ld PI = 4 * atan((ld)1);
int ans[MX];
bool end[MX];
void solve() {
  string s;
  re(s);
  fax(i, sz(s) - 1) {
    if (s[i] == '>' && s[i + 1] == '<') {
      ans[i + 1] = 0;
    }
  }
  fax(i, sz(s)) {
    if (s[i] == '<') {
      ans[i + 1] = max(ans[i + 1], ans[i] + 1);
    }
  }
  faxd(i, sz(s)) {
    if (s[i] == '>') {
      ans[i] = max(ans[i], ans[i + 1] + 1);
    }
  }
  ll ret = 0;
  fax(i, sz(s) + 1) { ret += ans[i]; }
  cout << ret << "\n";
}

int main() {
  setIO();
  int t = 1;
  while (t--) {
    solve();
  }
}


Fixed submission:
#pragma GCC optimize("O3")
#pragma GCC target("sse4")

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef pair<ld, ld> pd;
typedef pair<int, pi> pii;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

#define fax(i, a) for (int i = 0; i < (a); i++)
#define f0x(i, a, b) for (int i = (a); i < (b); i++)
#define f0xd(i, a, b) for (int i = (b)-1; i >= (a); i--)
#define faxd(i, a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto &a : x)
#define memeset memset

#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rsz resize

template <class T> void ckmin(T &a, T b) { a = min(a, b); }
template <class T> void ckmax(T &a, T b) { a = max(a, b); }

template <class T, int... Ns> struct BIT {
  T val = 0;
  void upd(T v) { val += v; }
  T query() { return val; }
};

template <class T, int N, int... Ns> struct BIT<T, N, Ns...> {
  BIT<T, Ns...> bit[N + 1];
  template <typename... Args> void upd(int pos, Args... args) {
    for (; pos <= N; pos += (pos & -pos))
      bit[pos].upd(args...);
  }
  template <typename... Args> T sum(int r, Args... args) {
    T res = 0;
    for (; r; r -= (r & -r))
      res += bit[r].query(args...);
    return res;
  }
  template <typename... Args> T query(int l, int r, Args... args) {
    return sum(r, args...) - sum(l - 1, args...);
  }
};

namespace input {
template <class T> void re(complex<T> &x);
template <class T1, class T2> void re(pair<T1, T2> &p);
template <class T> void re(vector<T> &a);
template <class T, size_t SZ> void re(array<T, SZ> &a);

template <class T> void re(T &x) { cin >> x; }
void re(double &x) {
  string t;
  re(t);
  x = stod(t);
}
void re(ld &x) {
  string t;
  re(t);
  x = stold(t);
}
template <class T, class... Ts> void re(T &t, Ts &...ts) {
  re(t);
  re(ts...);
}

template <class T> void re(complex<T> &x) {
  T a, b;
  re(a, b);
  x = cd(a, b);
}
template <class T1, class T2> void re(pair<T1, T2> &p) { re(p.f, p.s); }
template <class T> void re(vector<T> &a) { fax(i, sz(a)) re(a[i]); }
template <class T, size_t SZ> void re(array<T, SZ> &a) { fax(i, SZ) re(a[i]); }
} // namespace input

using namespace input;

namespace output {
void pr(int x) { cout << x; }
void pr(long x) { cout << x; }
void pr(ll x) { cout << x; }
void pr(unsigned x) { cout << x; }
void pr(unsigned long x) { cout << x; }
void pr(unsigned long long x) { cout << x; }
void pr(float x) { cout << x; }
void pr(double x) { cout << x; }
void pr(ld x) { cout << x; }
void pr(char x) { cout << x; }
void pr(const char *x) { cout << x; }
void pr(const string &x) { cout << x; }
void pr(bool x) { pr(x ? "true" : "false"); }

template <class T1, class T2> void pr(const pair<T1, T2> &x);
template <class T> void pr(const T &x);

template <class T, class... Ts> void pr(const T &t, const Ts &...ts) {
  pr(t);
  pr(ts...);
}
template <class T1, class T2> void pr(const pair<T1, T2> &x) {
  pr("{", x.f, ", ", x.s, "}");
}
template <class T> void pr(const T &x) {
  pr("{"); // const iterator needed for vector<bool>
  bool fst = 1;
  for (const auto &a : x)
    pr(!fst ? ", " : "", a), fst = 0;
  pr("}");
}

void ps() { pr("\n"); } // print w/ spaces
template <class T, class... Ts> void ps(const T &t, const Ts &...ts) {
  pr(t);
  if (sizeof...(ts))
    pr(" ");
  ps(ts...);
}

void pc() { pr("]\n"); } // debug w/ commas
template <class T, class... Ts> void pc(const T &t, const Ts &...ts) {
  pr(t);
  if (sizeof...(ts))
    pr(", ");
  pc(ts...);
}
#define dbg(x...) pr("[", #x, "] = ["), pc(x);
} // namespace output

using namespace output;

namespace io {
void setIn(string s) { freopen(s.c_str(), "r", stdin); }
void setOut(string s) { freopen(s.c_str(), "w", stdout); }
void setIO(string s = "") {
  ios_base::sync_with_stdio(0);
  cin.tie(0); // fast I/O
  if (sz(s)) {
    setIn(s + ".in"), setOut(s + ".out");
  } // for USACO
}
} // namespace io

using namespace io;

const int MOD = 1000000007; // 998244353
const ll INF = 1e18;
const int MX = 500005;
const ld PI = 4 * atan((ld)1);
int ans[MX];
bool end[MX];
void solve() {
  string s;
  re(s);
  fax(i, sz(s) - 1) {
    if (s[i] == '>' && s[i + 1] == '<') {
      ans[i + 1] = 0;
    }
  }
  fax(i, sz(s)) {
    if (s[i] == '<') {
      ans[i + 1] = max(ans[i + 1], ans[i] + 1);
    }
  }
  faxd(i, sz(s)) {
    if (s[i] == '>') {
      ans[i] = max(ans[i], ans[i + 1] + 1);
    }
  }
  ll ret = 0;
  fax(i, sz(s) + 1) { ret += ans[i]; }
  cout << ret << "\n";
}

int main() {
  setIO();
  int t = 1;
  while (t--) {
    solve();
  }
}