csu - 1537: Miscalculation (模拟题)

http://acm.csu.edu.cn/OnlineJudge/problem.php?id=1537

因为给出的式子是必定合法的,只要用两个栈分别保存符号和数字.算出答案后和从左至右算的答案比对即可.

 #include <iostream>
 #include <cstdio>
 #include <cmath>
 #include <vector>
 #include <cstring>
 #include <algorithm>
 #include <string>
 #include <set>
 #include <functional>
 #include <numeric>
 #include <sstream>
 #include <stack>
 #include <map>
 #include <queue>

 #define CL(arr, val)    memset(arr, val, sizeof(arr))

 #define ll long long
 #define inf 0x7f7f7f7f
 #define lc l,m,rt<<1
 #define rc m + 1,r,rt<<1|1
 #define pi acos(-1.0)

 #define L(x)    (x) << 1
 #define R(x)    (x) << 1 | 1
 #define MID(l, r)   (l + r) >> 1
 #define Min(x, y)   (x) < (y) ? (x) : (y)
 #define Max(x, y)   (x) < (y) ? (y) : (x)
 #define E(x)        (1 << (x))
 #define iabs(x)     (x) < 0 ? -(x) : (x)
 #define OUT(x)  printf("%I64d\n", x)
 #define lowbit(x)   (x)&(-x)
 #define Read()  freopen("din.txt", "r", stdin)
 #define Write() freopen("dout.txt", "w", stdout);

 using namespace std;

 int main()
 {
     //freopen("a.txt","r",stdin);
     char s[];
     int num;
     scanf("%s",s);
     scanf("%d",&num);
     stack<int>s1;
     stack<char>s2;
     int l=strlen(s);
     for(int i=;i<l;i++)
     {
         if(s[i]>=''&&s[i]<='') s1.push(s[i]-'');
         else if(s[i]=='*')
         {
             int x=s1.top();s1.pop();
             int y=s[i+]-'';
             s1.push(x*y);
             i++;
         }
         else s2.push('+');
     }
     while(!s2.empty())
     {
         int x=s1.top();s1.pop();
         int y=s1.top();s1.pop();
         s1.push(x+y);
         s2.pop();
     }
     int sum=s[]-'';
     for(int i=;i<l;i++)
     {
         if(s[i]=='+') sum=sum+(s[i+]-'');
         else if(s[i]=='*') sum=sum*(s[i+]-'');
     }
     //printf("%d %d\n",s1.top(),sum);
     if(s1.top()==sum&&sum==num) printf("U\n");
     else if(s1.top()!=num&&sum!=num) printf("I\n");
     else if(s1.top()==num&&sum!=num) printf("M\n");
     else if(s1.top()!=num&&sum==num) printf("L\n");
     return ;
 }