87 lines
2.2 KiB
C
87 lines
2.2 KiB
C
#include <stdio.h>
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#include<stdlib.h>
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#include <string.h>
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#include <assert.h>
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#define STACK_SIZE 10000
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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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struct stack mystack;
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void push_stack(struct stack* stack, float value){
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assert(stack->size < STACK_SIZE);
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stack->values[stack->size] = value;
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stack->size += 1;
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}
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float pop_stack(struct stack* stack){
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assert(stack->size > 0);
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float value = stack->values[stack->size-1];
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stack->size -= 1;
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return value;
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}
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void print_stack(struct stack* stack){
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for(int i = 0; i < stack->size; i++)
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printf("%.2f ", stack->values[i]);
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printf("\n");
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}
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void process_operations(struct stack* stack) {
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char line[STACK_SIZE];
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int could_read = 0;
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while (fgets(line, sizeof(line), stdin)) {
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could_read= 1;
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line[strcspn(line, "\n")] = '\0';
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if (line == '\0')
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{printf("no input\n");
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return;
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}
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if ((strcmp(line, "+") == 0 || strcmp(line, "-") == 0 ||
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strcmp(line, "*") == 0 || strcmp(line, "/") == 0)) {
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if (stack->size >= 2) {
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float b = pop_stack(stack);
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float a = pop_stack(stack);
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if (line[0] == '/' && b == 0.0F)
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{
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printf("division by zero\n");
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return;
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}
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float res = (line[0] == '+') ? a + b :
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(line[0] == '-') ? a - b :
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(line[0] == '*') ? a * b :
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(line[0] == '/') ? a / b : 0;
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push_stack(stack, res);
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print_stack(stack);
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} else {
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printf("bad input\n");
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return;
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}
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} else {
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char *endptr;
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float val = strtof(line, &endptr);
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if (endptr == line) {
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printf("no input\n");
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return;
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}
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push_stack(stack, val);
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print_stack(stack);
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}
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}
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if (!could_read) {
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printf("no input\n");
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}
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printf("no input\n");
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}
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int main(void){
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memset(&mystack,0,sizeof(struct stack));
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process_operations(&mystack);
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} |