hdu 1237 简单计算器

普通方法

#include<iostream>
#include<string.h>
using namespace std;
char a[205], c[205];
double b[205];

int main()
{
	while(gets(a))
	{
		//if(!strcmp(a, "0"))
		//	break;
		memset(b, 0, sizeof(b));
		memset(c, 0, sizeof(c));
		int i, temp=0, t = 0, l;
		l = strlen(a);
		if(l == 1 && a[0] == '0')
		{
			exit(0);
		}
		double sum = 0;
		for( i=0; i < l; i++ )
		{
			if(a[i] >= '0' && a[i] <= '9')
				temp = temp*10 + a[i] - '0', b[t] = temp;
			else
				temp = 0;
			if(a[i] == '+' || a[i] == '-' || a[i] == '*' || a[i] == '/')
				c[t++] = a[i];
		}
		for( i=0; i < t; i++ )
		{
			if(c[i] == '*' || c[i] == '/')
			{
				if(c[i] == '*')
				{
					b[i+1] *= b[i];
					b[i] = 0;
					if(i-1 >= 0)
						c[i] = c[i-1];
					else
						c[i] = '+';
				}
				else
				{
					b[i+1] = b[i] / b[i+1];
					b[i] = 0;
					if(i-1 >= 0)
						c[i] = c[i-1];
					else
						c[i] = '+';
				}
			}
		}
		
		sum = b[0];
		for( i=0; i < t; i++ )
		{
			if(c[i] == '+')
				sum += b[i+1];
			else
				sum -= b[i+1];
		}
		printf("%.2lf\n", sum);
	}

	return 0;
}