91 lines
2.1 KiB
C
91 lines
2.1 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <ctype.h>
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#define STACK_SIZE 10
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struct stack {
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float values[STACK_SIZE];
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int size;
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};
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void init(struct stack *s){
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s->size=0; //inicializacia stacku
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}
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int is_empty(struct stack *s){return s->size==0;} // check if stack is empty
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int is_full(struct stack *s){return s->size==STACK_SIZE;}
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void push(struct stack *s, float value){
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if (is_full(s)){
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printf("full stack\n");
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exit(0);
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}
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s->values[s->size++]=value; // pridava cislo do stacku a size +=1
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}
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float pop (struct stack *s){
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if (is_empty(s)){
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printf("Stack is empty");
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return 1;
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}
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return s->values[--(s->size)]; // najprv - size, potom vybera jednu polozku
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}
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void print_s(struct stack *s){
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for(int i =0;i<s->size;i++){
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printf("%.2f ", s->values[i]);
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}
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printf("\n");
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}
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int main(){
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struct stack mystack;
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init(&mystack);
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char input[100];
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while(fgets(input, sizeof(input), stdin)){
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input[strcspn(input,"\n")]='\0';
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char *endpt;
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float num = strtod(input,&endpt); // oddeli vsetky cisla (medzerami) a posledne zapise do endpt
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if(endpt!=input&&*endpt=='\0'){ // ked endpt!= plnomu inputu a nie je koncom inputu
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push(&mystack,num);
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}
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else if (strlen(input)==1&&strchr("+-*/",input[0])){ // ak dlzka inputu po upravach 1 a to nojeaky operator
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if (mystack.size<2){ // previerka na to ci mame cisla pre operacie
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printf("not enough operands\n");
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return 0;}
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float b=pop(&mystack);
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float a = pop(&mystack);
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float result = 0;
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if (input[0]=='+') result=a+b;
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if (input[0]=='-') result=a-b;
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if (input[0]=='*') result=a*b;
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if (input[0]=='/'){
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if (b==0) {printf("division by zero\n");return 0;}
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result=a/b;
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}
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push(&mystack, result);
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}
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else{
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printf("bad input\n");
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return 0;
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}
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print_s(&mystack);
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}
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printf("no input\n");
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return 0;
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}
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