Page 257 - Computer Science Class 11 With Functions
P. 257

Program 10.13 To display the inverted isosceles triangular pattern of a symbol.

              01 def invertedIsoTriangle(nRows, symbol):
              02     '''
              03     Objective: To display an inverted isosceles triangular pattern
              04     Inputs:
              05       nRows : number of rows
              06       symbol: symbol to be printed
              07     Return value: None
              08     '''
              09     #Approach: In each line,
              10     #          first print enough blanks, then enough symbols
              11
              12     nSpaces = 0
              13     nSymbols = 2 * nRows - 1
              14
              15     for i in range(nRows):
              16         print(' ' * nSpaces, end = '')
              17         print(symbol * nSymbols)
              18         nSpaces = nSpaces + 1
              19          nSymbols = nSymbols - 2
              20 invertedIsoTriangle(6, '*')
            Sample Output:
                  ***********
                   *********
                    *******
                     *****
                      ***
                       *
            Fig 10.6: Inverted Isosceles Triangle
            Next, let us write a function to print an isosceles triangle using a given symbol (say, symbol). Fig 10.7 shows an
                                                                                     th
            isosceles triangle comprising six rows using asterisks. Note that the last row (6  row) does not have any leading
                    th
                                                   th
            spaces, 5  row has one leading space, the 4  row has two leading spaces, and so on. Finally, the first row has 5 (=6-1)
                         th
            spaces. Thus, i  row has nRows-i leading spaces. Furthermore, the first row has one asterisk, the second row has
                                                                                th
            3 asterisks, and so on. Finally, the sixth row has 11 (=6×2-1) asterisks. Thus, i  row has 2×i-1 asterisks. Now we are
            ready to write a function to display an isosceles triangle.
            Program 10.14 Write a function isoscelesTriangle(nRows,symbol) to display the isosceles triangular pattern
            of a symbol.

              01 def isoscelesTriangle(nRows, symbol):
              02     '''
              03     Objective: To display an isosceles triangular pattern of a symbol
              04     Inputs:
              05       nRows : number of rows
              06       symbol: symbol to be printed
              07     Return value: None
              08     '''
              09     #Approach: In each line,
              10     #          first print enough blanks, then enough symbols
              11
              12     nSpaces = nRows-1
              13     nSymbols = 1
              14     for row in range(1, nRows + 1):
              15         print(' ' * nSpaces, end = '')
              16         print(symbol * nSymbols)


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