Calculates the number of times a number appears in a value range and the number of times a value range appears.

Calculates the number of times a number appears in a value range and the number of times a value range appears.

Calculates the number of times a number 9 appears in a numerical range.

1. Program Implementation

2. Function Testing

3 program optimization

4. Add debugging code

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1. Program Implementation

Vim 9.c

Gcc 9.c

./A. out

The image is too large. Change the number of columns to 10.

2. Function Testing

Test whether the 9 value in a number can be accurately determined.

Modify:

Min = 9938; Max = 9939;

......

./A. out

Display num: 9 in 9938 and 9939. There are. | 9938 9939 From 9938 to 9939 have num 9 is: 5

3 program optimization

Learn a piece of code from the experts and make a modification record.

While (jj) { If (j = ii % 10) K ++; // Ii = (ii-ii % 10)/10; // If (ii <jj) // Jj = 0; Ii = ii/10; If (ii = ii/10) Jj = 0; }

4. Add debugging code

Add the debugging code and modify the code as follows: (the original Lines 18 and 51; add line "well)

# If t Printf ("Display num: % d in % d and % d. \ n \ tThere are. \ n \ t |", j, min, max ); # Endif

# If t Printf ("% 6d", I ); # Endif

Compile:

Gcc 9.c-Dt-o 1

Gcc 9.c-Ut-o 2

./1

Display num: 9 in 9938 and 9939. There are. | 9938 9939 From 9938 to 9939 have num 9 is: 5

./2

From 9938 to 9939 have num 9 is: 5