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This article will explain in detail how to use the sequence stack to judge palindromes in C language. The editor thinks it is very practical, so I share it for you as a reference. I hope you can get something after reading this article.

I used two stacks worth comparing the size of the judgment (may be a waste of space, but the code I feel a little simpler)

The first is to define the structural elements of a stack. Since it is a string type, you can directly define an array of char:.

Typedef struct stack {char data [Max _ SIZE]; / / Storage string / / int top; / / Top of record Stack / /} SeqStack

The next step is initialization. I use teacher Geng Guohua's method here to give a top element directly to the top of the stack, passing in the pointer address:.

Void Initstack (SeqStack * S) / / initialize the stack so that top points to the top of the stack / / {S-> top=-1;}

Here's how to create a sequential stack, where elements can always be checked in as long as they are not full:

Int Push (SeqStack * S return char x) / / Stack, as long as top is less than MAX_SIZE-1, you can continue to stack / / {if (S-> toptop++; S-> data [S-> top] = x;} else {return-1 politics;}}

The following is the core function, the operation to achieve the judgment of palindromes, I commented more clearly and directly read it:

Void Pop (SeqStack* S) / / unstack operation, which is also the main operation / / {SeqStack* p; p = (SeqStack*) malloc (sizeof (SeqStack)); / / create a new empty stack, because it is a pointer type to assign a dynamic address / / Initstack (p) / / initialize the new stack / / int istack S-> top/2; / / I is used to split two strings and assign the second string to the new empty stack / / int j=i-1 / / j is used to record the number of characters other than @. / / while (S-> topstack roomi) / / begins to assign values to the empty stack and starts emptying the original stack (normal size) / / {p-> top++ P-> data [p-> top] = S-> data [S-> top]; S-> top--;} S-> top=S- > top-2; / / Let the original stack point directly to the number, crossing the character @ / / for (int kryp0) Kdata [S-> top] = = p-> data [p-> top]) / / because of the characteristics of the stack, the storage order of the new stack is the same as that of the old stack after the @ character is removed, so here we directly compare / / {JFI- / / j defines the size of characters to be compared. As long as the elements of the two stacks are equal, ASCLL is minus one. If all equal j is 0, the string is the palindrome sequence / /} S-> top-- of each other. / / two top pointers go down / / p-> top--; if (jackpot 0) / / judge / / {printf ("two strings are palindromes!") }} if (jackpot 0) {printf ("two strings are not palindromes!");} free (p); / / free lost allocated space / /}

The whole code is attached below:

# include#include#define MAX_SIZE 100typedef struct stack {char data [Max _ SIZE]; / / Store string / / int top; / / Top of record Stack / /} SeqStack;void Initstack (SeqStack * S) / / initialize the stack and let top point to the top of the stack / / {S-> top=-1 } int Push (SeqStack * S return x) / / Stack, as long as top is less than MAX_SIZE-1, you can continue to stack / / {if (S-> toptop++; S-> data [S-> top] = x;} else {return-1 ×;}} void Pop (SeqStack * S) / / unstack operation, which is also the main operation / / {SeqStack * p P = (SeqStack*) malloc (sizeof (SeqStack)); / / create a new empty stack, because it is a pointer type to assign a dynamic address / / Initstack (p); / / initialize the new stack / / int iStack S-> top/2 / / I is used to split two strings and assign the second string to the new empty stack / / int j=i-1 / / j is used to record the number of characters other than @. / / while (S-> topstack roomi) / / begins to assign values to the empty stack and starts emptying the original stack (normal size) / / {p-> top++ P-> data [p-> top] = S-> data [S-> top]; S-> top--;} S-> top=S- > top-2; / / Let the original stack point directly to the number, crossing the character @ / / for (int kryp0) Kdata [S-> top] = = p-> data [p-> top]) / / because of the characteristics of the stack, the storage order of the new stack is the same as that of the old stack after the @ character is removed, so here we directly compare / / {JFI- / / j defines the size of characters to be compared. As long as the elements of the two stacks are equal, ASCLL is minus one. If all equal j is 0, the string is the palindrome sequence / /} S-> top-- of each other. / / two top pointers go down / / p-> top--; if (jackpot 0) / / judge / / {printf ("two strings are palindromes!") }} if (jackers 0) {printf ("two strings are not palindromes for each other!");} free (p); / / free missing allocated space / /} int main () {SeqStack S; char x; int masks 0; Initstack (& S) Printf ("Please enter the first string of characters\ n"); while (masked characters 2) / / because you only need to enter the judgment of two strings, the judgment condition is m! = 2max / {scanf ("% c", & x); if (x = "% c", & x) / / enter @ to indicate the end of the first string / / {masks + If (masked characters 1) {printf ("Please enter the second string of characters:\ n");}} Push (& S);} Pop (& S); return 0;}

Let's add an example:

Judge whether 3x1 and 1p3 are palindromes

On "C language how to use the sequence stack to achieve palindromes sequence judgment" this article is shared here, I hope the above content can be of some help to you, so that you can learn more knowledge, if you think the article is good, please share it for more people to see.

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