Topic 1019: Simple Calculator

Topic 1019: Simple Calculator

time limit:1 seconds

Memory limit:32 MB

Special question: No

Title Description:

reads a non-negative integer that contains only a +,-, *,/, evaluates the expression, and computes the value of the expression.

Input:

The

test input contains several test cases, one row per test case, and no more than 200 characters per line, separated by a space between integers and operators. There is no illegal expression. When only 0 o'clock input is completed in a row, the corresponding result is not output.

Output:

Output 1 rows for each test case, that is, the value of the expression, exactly 2 digits after the decimal point.

Sample input:

1 + 24 + 2 * 5-7/110

Sample output:

3.0013.36

#include <iostream>#include<stdio.h>#include<stack>using namespacestd;Charstr[ -];intmat[][5]={    {1,0,0,0,0},    {1,0,0,0,0},//+{1,0,0,0,0},//-{1,1,1,0,0},//*{1,1,1,0,0}// /};stack<int> op;//operator stacks, saving operator numbersstack<Double>inch;voidGetop (BOOL&reto,int&AMP;RETN,int&i) {    if(i==0&&op.empty () = =true) {Reto=true; RETN=0; return ; }    if(str[i]==0) {Reto=true; RETN=0; return ; }    if(str[i]>='0'&&str[i]<='9') {Reto=false; }    Else{Reto=true; if(str[i]=='+') {Retn=1; }        Else if(str[i]=='-') {Retn=2; }        Else if(str[i]=='*') {Retn=3; }        Else if(str[i]=='/') {Retn=4; } I+=2;//Skip the operator and the space after the operator        return; } RETN=0;//returns the result as a number     for(; str[i]!=' '&&str[i]!=0; i++) {Retn*=Ten; RETN+=str[i]-'0'; }    if(str[i]==' ') I++; return ;}intMain () { while(gets (str)) {if(str[0]=='0'&&str[1]==0)        {             Break; }        BOOLRetop; intRetnum;//define the reference variables that the function needs to use        intidx=0;//string subscript         while(!op.empty ()) Op.pop ();//symbols         while(!inch. empty ())inch. Pop ();//Digital         while(true) {getop (RETOP,RETNUM,IDX); if(retop==false)            {                inch. Push (Double) retnum);//Press it into the digital stack            }            Else            {                Doubletmp; if(Op.empty () = =true|| Mat[retnum][op.top ()]==1) {Op.push (retnum); }                Else                {                     while(Mat[retnum][op.top ()]==0)                    {                        intRet=op.top ();//save symbol Stack top elementOp.pop (); Doubleb=inch. Top (); inch. Pop (); DoubleA=inch. Top (); inch. Pop (); if(ret==1) tmp=a+b; Else if(ret==2) tmp=a-b; Else if(ret==3) tmp=a*C; Elsetmp=a/b; inch. push (TMP);//press the number onto the stack} op.push (Retnum); }            }            if(op.size () = =2&&op.top () = =0) Break; } printf ("%.2f\n",inch. Top ()); }    return 0;}/************************************************************** problem:1019 User:zhuoyuezai language:c++ result:accepted time:0 Ms memory:1524 kb****************************************************************/

Topic 1019: Simple Calculator