Problem p02696 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <stack>
#include <stdio.h>
#include <string>
#include <utility>
#include <vector>

using namespace std;

// conversion
//------------------------------------------
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}

// math
//-------------------------------------------
template <class T> inline T sqr(T x) { return x * x; }

// typedef
//------------------------------------------
typedef long long LL;

typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<string, int> PSI;

// container util
//------------------------------------------
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i, c)                                                             \
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())

// repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define REP(i, n) for (int i = 0; i < (n); i++)

// constant
//--------------------------------------------
const double PI = acos(-1.0);

// clear memory
#define CLR(a) memset((a), 0, sizeof(a))

// debug
#define dump(x) cerr << #x << " = " << (x) << endl;
#define debug(x)                                                               \
  cerr << #x << " = " << (x) << " (L" << __LINE__ << ")"                       \
       << " " << __FILE__ << endl;
const LL MOD = 1e9 + 7;
// vector <vector<int>> x(20, vector<int> (20)), y(20,vector<int> (20));
/*int counter_1 (int x) {
    if(x == 0) return 0;
    return counter_1(x >> 1) + (x & 1);
}*/

// int Counter(int x)
/*int factorial(int n) {
    if (n > 0) {
        return n * factorial(n - 1);
    } else {
        return 1;
    }
}*/
/*bool pairCompare(const P& firstElof, const P& secondElof)
{
    return firstElof.second > secondElof.second;
}*/

/*long nCr(int n, int r)
{
       if(n==r) return dp[n][r] = 1;
       if(r==0) return dp[n][r] = 1;
       if(r==1) return dp[n][r] = n;
       if(dp[n][r]) return dp[n][r];
       return dp[n][r] = nCr(n-1,r) + nCr(n-1,r-1);
}*/
/*int stoi(std::string str){
int ret;
std::stringstream ss;
ss << str;
ss >> ret;
return ret;
}*/
void Main() {
  LL n, a, b;
  cin >> a >> b >> n;
  LL ans = 0;
  LL x = min(b - 1, n);
  double af = 0.0;
  FOR(i, 1, x + 1) {
    double f = i / (double)b;
    LL z = i / b;
    // cout << f << endl;
    af = max(f - double(z), af);
  }
  ans = (a * af) / 1;
  cout << ans << endl;
}
int main() {
  cin.tie(nullptr);
  ios_base::sync_with_stdio(false);
  cout << fixed << setprecision(0);
  Main();
}


Fixed submission:
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <stack>
#include <stdio.h>
#include <string>
#include <utility>
#include <vector>

using namespace std;

// conversion
//------------------------------------------
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}

// math
//-------------------------------------------
template <class T> inline T sqr(T x) { return x * x; }

// typedef
//------------------------------------------
typedef long long LL;

typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<string, int> PSI;

// container util
//------------------------------------------
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i, c)                                                             \
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())

// repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define REP(i, n) for (int i = 0; i < (n); i++)

// constant
//--------------------------------------------
const double PI = acos(-1.0);

// clear memory
#define CLR(a) memset((a), 0, sizeof(a))

// debug
#define dump(x) cerr << #x << " = " << (x) << endl;
#define debug(x)                                                               \
  cerr << #x << " = " << (x) << " (L" << __LINE__ << ")"                       \
       << " " << __FILE__ << endl;
const LL MOD = 1e9 + 7;
// vector <vector<int>> x(20, vector<int> (20)), y(20,vector<int> (20));
/*int counter_1 (int x) {
    if(x == 0) return 0;
    return counter_1(x >> 1) + (x & 1);
}*/

// int Counter(int x)
/*int factorial(int n) {
    if (n > 0) {
        return n * factorial(n - 1);
    } else {
        return 1;
    }
}*/
/*bool pairCompare(const P& firstElof, const P& secondElof)
{
    return firstElof.second > secondElof.second;
}*/

/*long nCr(int n, int r)
{
       if(n==r) return dp[n][r] = 1;
       if(r==0) return dp[n][r] = 1;
       if(r==1) return dp[n][r] = n;
       if(dp[n][r]) return dp[n][r];
       return dp[n][r] = nCr(n-1,r) + nCr(n-1,r-1);
}*/
/*int stoi(std::string str){
int ret;
std::stringstream ss;
ss << str;
ss >> ret;
return ret;
}*/
void Main() {
  LL n, a, b;
  cin >> a >> b >> n;
  LL ans = 0;
  LL x = min(b - 1, n);
  double af = 0.0;
  double f = x / (double)b;
  LL z = x / b;
  // cout << f << endl;
  af = f - double(z);
  ans = (a * af) / 1;
  cout << ans << endl;
}
int main() {
  cin.tie(nullptr);
  ios_base::sync_with_stdio(false);
  cout << fixed << setprecision(0);
  Main();
}