Added more example programs

Author: cpp-tutor

progs/chars.psc

@@ -1,7 +1,9 @@
+# Output all ASCII 7-bit (UTF-7) characters from 32 to 127, in a table
+
 FOR page <- 32 TO 112 STEP 16
-s <- ''
-FOR char <- 0 TO 15
-s <- s + CODE_TO_CHAR(page + char) + ' '
-ENDFOR
-OUTPUT s
+  s <- ''
+  FOR char <- 0 TO 15
+    s <- s + CODE_TO_CHAR(page + char) + ' '
+  ENDFOR
+  OUTPUT s
 ENDFOR

progs/circle.psc

@@ -1,16 +1,16 @@
-CONSTANT PI <- 3.14
+# Calculate circumference and area of a circle using formulas
+
+CONSTANT PI <- 3.1416
 
 SUBROUTINE circumference(radius : Real)
-RETURN 2.0 * PI * radius
+  RETURN 2.0 * PI * radius
 ENDSUBROUTINE
 
 SUBROUTINE area(radius : Real)
-RETURN PI * radius * radius
+  RETURN PI * radius * radius
 ENDSUBROUTINE
 
-FOR n <- 1 TO 4
-OUTPUT 'Please enter the radius:'
+OUTPUT 'Please enter the radius of the circle:'
 r <- STRING_TO_REAL(USERINPUT)
 OUTPUT 'Circumference is: ' + REAL_TO_STRING(circumference(r))
 OUTPUT 'Area is: ' + REAL_TO_STRING(area(r))
-ENDFOR

progs/compare.psc

@@ -0,0 +1,30 @@
+# Compare two Integers with all the boolean tests supported
+
+SUBROUTINE BOOL_TO_STRING(condition : Boolean)
+  IF condition THEN
+    str <- 'True'
+  ELSE
+    str <- 'False'
+  ENDIF
+  RETURN str
+ENDSUBROUTINE
+
+OUTPUT 'Please enter an Integer:'
+a <- STRING_TO_INT(USERINPUT)
+OUTPUT 'Please enter one more Integer:'
+b <- STRING_TO_INT(USERINPUT)
+OUTPUT 'Sum: ' + INT_TO_STRING(a + b)
+difference <- a - b
+IF difference < 0 THEN
+  difference <- -difference
+ENDIF
+OUTPUT 'Difference: ' + INT_TO_STRING(difference)
+OUTPUT 'Product: ' + INT_TO_STRING(a * b)
+OUTPUT 'Result of division: ' + INT_TO_STRING(a DIV b) + ', remainder: ' + INT_TO_STRING(a MOD b)
+
+OUTPUT INT_TO_STRING(a) + ' = ' + INT_TO_STRING(b) + ': ' + BOOL_TO_STRING(a = b)
+OUTPUT INT_TO_STRING(a) + ' /= ' + INT_TO_STRING(b) + ': ' + BOOL_TO_STRING(a /= b)
+OUTPUT INT_TO_STRING(a) + ' < ' + INT_TO_STRING(b) + ': ' + BOOL_TO_STRING(a < b)
+OUTPUT INT_TO_STRING(a) + ' <= ' + INT_TO_STRING(b) + ': ' + BOOL_TO_STRING(a <= b)
+OUTPUT INT_TO_STRING(a) + ' >= ' + INT_TO_STRING(b) + ': ' + BOOL_TO_STRING(a >= b)
+OUTPUT INT_TO_STRING(a) + ' > ' + INT_TO_STRING(b) + ': ' + BOOL_TO_STRING(a > b)

progs/find.psc

@@ -0,0 +1,11 @@
+# Program which finds tries to find the letter "a" in a string
+
+OUTPUT 'Please enter a word containing the letter "a":'
+word <- USERINPUT
+OUTPUT 'Word has ' + INT_TO_STRING(LEN(word)) + ' letters'
+position <- POSITION(word, 'a')
+IF position > 0 THEN
+  OUTPUT 'Found "a" at position: ' + INT_TO_STRING(position)
+ELSE
+  OUTPUT 'Word does not contain the letter "a"'
+ENDIF

progs/guess.psc

@@ -0,0 +1,30 @@
+# Guess a number between 1 and 100 in seven or fewer attempts
+
+CONSTANT MIN <- 1
+CONSTANT MAX <- 100
+str <- USERINPUT
+IF str /= '' THEN
+  number_to_find <- STRING_TO_INT(str)
+ELSE
+  number_to_find <- RANDOM_INT(MIN,MAX)
+ENDIF
+OUTPUT 'Try to find: ' + INT_TO_STRING(number_to_find)
+
+guess <- 0
+attempts <- 0
+low <- MIN
+high <- MAX
+WHILE guess /= number_to_find
+  guess <- low + (high - low) DIV 2
+  attempts <- attempts + 1
+  OUTPUT 'Guessed: ' + INT_TO_STRING(guess)
+  IF guess > number_to_find THEN
+    OUTPUT 'Too high.'
+    high <- guess - 1
+  ELSE IF guess < number_to_find THEN
+    OUTPUT 'Too low.'
+    low <- guess + 1
+  ELSE
+    OUTPUT 'Got it in ' + INT_TO_STRING(attempts) + ' attempts!'
+  ENDIF
+ENDWHILE

progs/hello.psc

@@ -1,3 +1,5 @@
+# Simple "Hello world" program which accepts input
+
 OUTPUT 'Please enter your name:'
 name <- USERINPUT
 OUTPUT 'Hi, ' + name + '! How are you today?'

progs/matrix.psc

@@ -0,0 +1,39 @@
+# Transforms an (x,y) co-ordinate using 2-by-2 matrix multiplication
+
+OUTPUT 'Please enter x co-ordinate:'
+x <- STRING_TO_REAL(USERINPUT)
+OUTPUT 'Please enter y co-ordinate:'
+y <- STRING_TO_REAL(USERINPUT)
+OUTPUT 'Please choose from:'
+OUTPUT '  1) Reflection in x-axis'
+OUTPUT '  2) Reflection in y-axis'
+OUTPUT '  3) Scale by factor 2'
+OUTPUT '  4) Rotation 90 degrees (anti-clockwise)'
+transform <- STRING_TO_INT(USERINPUT)
+
+matrix <- [[0.0, 0.0], [0.0, 0.0]]
+
+IF transform = 1 THEN
+  OUTPUT 'Reflection in x-axis'
+  matrix[0][0] <- 1.0
+  matrix[1][1] <- -1.0
+ELSE IF transform = 2 THEN
+  OUTPUT 'Reflection in y-axis'
+  matrix[0][0] <- -1.0
+  matrix[1][1] <- 1.0
+ELSE IF transform = 3 THEN
+  OUTPUT 'Scale by factor 2'
+  matrix[0][0] <- 2.0
+  matrix[1][1] <- 2.0
+ELSE IF transform = 4 THEN
+  OUTPUT 'Rotation by 90 degrees (anti-clockwise)'
+  matrix[0][1] <- -1.0
+  matrix[1][0] <- 1.0
+ELSE
+  OUTPUT 'Bad option'
+ENDIF
+
+x_t <- x * matrix[0][0] + y * matrix[0][1]
+y_t <- x * matrix[1][0] + y * matrix[1][1]
+
+OUTPUT 'Transformed: (' + REAL_TO_STRING(x_t) + ',' + REAL_TO_STRING(y_t) + ')'

progs/primes.psc

@@ -0,0 +1,32 @@
+# Find the sum of the first N prime numbers
+
+OUTPUT 'Please enter the number of primes to find:'
+str <- USERINPUT
+IF str /= '' THEN
+  primes <- STRING_TO_INT(str)
+ELSE
+  OUTPUT 'Okay, I chose 100'
+  primes <- 100
+ENDIF
+total <- 0
+printout <- ''
+n <- 2
+WHILE primes > 0
+  is_prime <- True
+  p <- 2
+  WHILE p * p <= n
+    IF n MOD p = 0 THEN
+      is_prime <- False
+    ENDIF
+    p <- p + 1
+  ENDWHILE
+  IF is_prime THEN
+    printout <- printout + INT_TO_STRING(n) + ' '
+    total <- total + n
+    primes <- primes - 1
+  ENDIF
+  n <- n + 1
+ENDWHILE
+
+OUTPUT 'Sum: ' + INT_TO_STRING(total)
+OUTPUT printout