Programming challenges

110101.cpp

//The 3n+1 problem

#include <iostream>
#include <cstdio>
using namespace std;

int limit = 999999;
int len[999999];

int get_cycle_len(long long int n){
   int clen = 0;
   if(n <= limit){
      if(len[n-1] != 0) return len[n-1];
      if(n%2 == 0) clen = 1 + get_cycle_len(n/2);  
      else  clen = 2 + get_cycle_len((n*3 + 1)/2);
      len[n-1] = clen;
   }
   else{
      if(n%2 == 0)  return 1 + get_cycle_len(n/2);  
      else return 2 + get_cycle_len((n*3 + 1)/2);
   }
   return clen; 
}

int get_max(int a, int b){
   int max = 1;
   int tmp;
   for(int i = a; i <= b; i++){
      if((tmp = len[i-1]) > max) max = tmp;
   }   
   return max;
}

int main()
{
   int d1, d2, tmp;
   int n = 2;
   len[0] = 1;
   while(n <= limit){
      if(n%2 == 0){
         len[n-1] = 1 + len[n/2-1];
         n++;
      }
      else get_cycle_len(n++);
   }   
   while ( scanf("%d %d", &d1, &d2) != EOF )
    {
      if (d1 < d2) cout << d1 << " " << d2 << " " << get_max(d1, d2) << endl;
      else cout << d1 << " " << d2 << " " << get_max(d2, d1) << endl;
    }  
   return 0;
}

110102.cpp

//The minesweeper problem

#include <iostream>
#include <cstdio>
#include <string>
using namespace std;

string to_string(int number){
    string number_string = "";
    char ones_char;
    int ones = 0;
    while(true){
        ones = number % 10;
        switch(ones){
            case 0: ones_char = '0'; break;
            case 1: ones_char = '1'; break;
            case 2: ones_char = '2'; break;
            case 3: ones_char = '3'; break;
            case 4: ones_char = '4'; break;
            case 5: ones_char = '5'; break;
            case 6: ones_char = '6'; break;
            case 7: ones_char = '7'; break;
            case 8: ones_char = '8'; break;
            case 9: ones_char = '9'; break;
            default : ones_char = '0';
        }
        number -= ones;
        number_string = ones_char + number_string;
        if(number == 0){
            break;
        }
        number = number/10;
    }
    return number_string;
}

string process_field(int m, int n, int k){
   string res = "";

   

   int arr[m+2][n+2];
   char tmp[n];
   for(int i =0; i< m+2; i++){
      for(int j = 0; j< n+2; j++){
         arr[i][j] = 0;
      }
   }

   for(int i =0; i < m; i++){
      scanf("%s", &tmp);
      for(int j = 0; j< n; j++){
         if(tmp[j]=='*'){
            arr[i+1][j+1] = -10;
            arr[i][j]++;
            arr[i][j+1]++;
            arr[i][j+2]++;
            arr[i+1][j]++;
            arr[i+1][j+2]++;
            arr[i+2][j]++;
            arr[i+2][j+1]++;
            arr[i+2][j+2]++;            
         } 
      }         
   }
   res = "Field #" + to_string(k) + ":\n";
   for(int i = 1; i< m+1; i++){
      for(int j = 1; j< n+1; j++){
         if(arr[i][j] < 0) res += string("*");
         else res+= to_string(arr[i][j]);
      }
      res += string("\n");
   }
   
   return res;
}

int main()
{
   int m,n;
   int k = 1;
   string res = "";
   while (true)
   {
      scanf("%d%d", &m, &n);
      if(m*n == 0) break;
      if(k!=1) res += string("\n");
      res += process_field(m,n, k++);      
   } 
   cout << res;
   return 0;
}

110103.cpp

//The trip problem

#include <iostream>
#include <cstdio>
#include <math.h>
using namespace std;

string to_string(int number){
    string number_string = "";
    char ones_char;
    int ones = 0;
    while(true){
        ones = number % 10;
        switch(ones){
            case 0: ones_char = '0'; break;
            case 1: ones_char = '1'; break;
            case 2: ones_char = '2'; break;
            case 3: ones_char = '3'; break;
            case 4: ones_char = '4'; break;
            case 5: ones_char = '5'; break;
            case 6: ones_char = '6'; break;
            case 7: ones_char = '7'; break;
            case 8: ones_char = '8'; break;
            case 9: ones_char = '9'; break;
            default : ones_char = '0';
        }
        number -= ones;
        number_string = ones_char + number_string;
        if(number == 0){
            break;
        }
        number = number/10;
    }
    return number_string;
}

string to_fstring(int number){
   int tmp = number%100;
   if(tmp >=10) return to_string(int(floor(number/100))) + "." + to_string(tmp);
   else return to_string(int(floor(number/100))) + "." + "0" + to_string(tmp) ;
}


string process_trip(int n){
   int sum = 0;
   int data[n];
   float tmp;
   for(int i = 0; i < n; i++){
      scanf("%f", &tmp);    
      data[i] = round(tmp*100);
      sum += data[i];
      //cout << sum << " " << tmp << " " << data[i] <<endl;
   }
   int avg = sum/n;
   int remain = sum%n;
   int res = 0;
   for(int i = 0; i < n; i++){
      if(avg >= data[i]) res += avg - data[i];
      else if(remain > 0) remain--;
   }
   return "$" + to_fstring(res + remain);
}

int main()
{
   int n;
   int k = 1;
   string res = "";
   while (true)
   {
      scanf("%d", &n);
      if(n == 0) break; 
      res += process_trip(n) + "\n";      
   } 
   cout << res;
   return 0;
}