九度+计算表达式模拟+scanf读取数据的灵活运用和运算级的处理

///不带括号的运算。以及对scanf读取数据深刻理解而运用。
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<string>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<math.h>
#include<cstdio>
#define maxn 2050
#define INF 0x3f3f3f3f
#define mod 1e9+7
#define LL long long
#define MAX 2000
using namespace std;
float Stack[MAX];
int tail = 0;
int main()
{
int a;
///ifstream cin("data.txt");
while (scanf("%d",&a)!=EOF){
tail = 0;
Stack[tail] = (float)a;
char algo = getchar();  ///algo表示运算符或者换行符
while (algo != '\n' && (algo =='+'||algo =='-'||algo=='*'||algo =='/')){///这儿要加上判断是否是运算符符号的条件
scanf("%d", &a);
if (algo == '+')///这里就是计算顺序。
Stack[++tail] = (float)a;
else if (algo == '-')
Stack[++tail] = -(float)a;
else if (algo == '*')
Stack[tail] = Stack[tail] * (float)a;
else if (algo == '/')
Stack[tail] = Stack[tail] / (float)a;
algo = getchar();
}
int result = 0;
for (int i = 0; i <= tail; i++)
result += Stack[i];
printf("%d\n", result);
}
return 0;
}