usaa20/cv3/program.c

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2020-10-11 12:27:21 +00:00
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define STACK_SIZE 100
struct stack {
float values[STACK_SIZE];
int size;
};
void push(struct stack* stack,float values){
assert(stack->size < STACK_SIZE);
stack->values[stack->size] = values;
stack->size += 1;
}
float pop(struct stack *stack){
assert(stack->size > 0);
float values = stack->values[stack->size-1];
stack->size -= 1;
return values;
}
void print_stack(struct stack *stack){
int i;
int len = stack->size - 1;
for(i = 0; i < len; i++){
printf("%0.2g ", stack->values[i]);
}
if(stack->size != 0){
printf("%0.2g ", stack->values[i]);
}
printf("\n");
}
int main() {
struct stack mystack;
memset(&mystack, 0, sizeof(struct stack));
int i = 0;
for(i = 0; i < 10000; i++){
char line[10];
char *x = fgets(line, 10, stdin);
float r = 0;
if(!isdigit(line[0]) && line[0] != '+' && line[0] != '*' && line[0] != '/' && line[0] != '-'){
return 0;
}
if(line[0] == '+'){
r = pop(&mystack) + pop(&mystack);
}
else if(line[0] == '-'){
r = pop(&mystack) - pop(&mystack);
}
else if(line[0] == '*'){
r = pop(&mystack) * pop(&mystack);
}
else if(line[0] == '/'){
r = pop(&mystack) / pop(&mystack);
}
else {
r = strtof(line,&x);
}
push(&mystack,r);
print_stack(&mystack);
}
return 0;
}