72 lines
1.3 KiB
C
72 lines
1.3 KiB
C
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#include<stdio.h>
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#include<string.h>
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char stack[50][50];
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int top = -1;
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void clear_stack()
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{
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top = -1 ;
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}
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void push(char *s)
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{
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strcpy(stack[++top], s) ;
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}
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char* pop()
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{
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return stack[top--];
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}
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int is_operator(char x)
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{
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if(x == '+' ||x == '-'||x == '*'||x == '/')
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{
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return 1;
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}
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else
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{
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return 0;
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}
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}
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//function to Convert prefix to Postfix
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void convert(char *exp)
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{
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clear_stack() ;
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int i,l;
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char op1[50],op2[50];
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l = strlen(exp);
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//scanning from right to left
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for(i = l - 1; i >= 0; i--)
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{
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//checking if the symbol is an operator
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if (is_operator(exp[i]))
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{
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//popping two operands from stack
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strcpy(op1, pop()) ;
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strcpy(op2, pop()) ;;
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//concating the operands and operator
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strcat(op1 , strcat(op2 , (char[2]) {(char)exp[i], '\0'})) ;
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//Pushing the temporary string to stack
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push(op1);
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}
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//if it is an operand
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else
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{
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//push the operand to the stack
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push((char[2]){(char)exp[i], '\0'});
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}
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}
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//printf("The postfix expression is: %s",stack[top].c_str());
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printf("%s\n",stack[top]);
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}
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int main()
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{
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char exp[50];
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printf("Enter the prefix expression: ");
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scanf("%s",exp);
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convert(exp);
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return 0;
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}
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