#include <math.h>                                           
   #define  LAMDA   0.001                                      
   main()                                                      
   {   
  double t;                                               
       float r;                                                
       int  i, R;                                              
       for (i=1; i<=27; ++i) 
       {
printf("--");
       }                                                       
       printf("\n");                                           
       for (t=0; t<=3000; t+=150)                              
       { 
r = exp(-LAMDA*t);                                  
           R = (int)(50*r+0.5);                                
           printf(" |");                                       
           for (i=1; i<=R; ++i)
           {
   printf("*");                                    
           }     
                                              
           printf("#\n");                                      
       }  
       for (i=1; i<3; ++i)  
       {
printf(" |\n"); 
       } 
                                                      
   }  
                                                         
 

Output                                                      
    -----------------------------------------------------      
    |**************************************************#       
    |*******************************************#              
    |*************************************#                    
    |********************************#                         
    |***************************#                           
    |************************#                                 
    |********************#                                     
    |*****************#                                        
    |***************#                                          
    |*************#                                          
    |***********#                                              
    |**********#                                               
    |********#                                                 
    |*******#                                                  
    |******#                                                   
    |*****#                                                    
    |*****#                                                    
    |****#                                                     
    |***#                                                      
    |***#                                                      
    |**#