HDU1296 Polynomial Problem

http://acm.hdu.edu.cn/showproblem.php?pid=1296

随手练习

 #include <bits/stdc++.h>
 using namespace std;
 #define ll long long
 int n;
 char s[];
 ll Solve(string s,int i)
 {
     ll num=;
     int l=i-;
     int r=i+;
     string s1="";
     while(s[l]>=''&&s[l]<='')
     {
         s1+=s[l];
         l--;
     }
     reverse(s1.begin(),s1.end());
     ll ans=;
     ll sum=;
     int len=s1.length();
     for(int j=; j<len; j++)
     {
         ans*=;
         ans+=(s1[j]-'');
     }
     if(ans==){
         ans=;

     }
     if(s[r]=='^')
     {
         r++;
         while(s[r]>=''&&s[r]<='')
         {
             sum*=;
             sum+=(s[r]-'');
             r++;
         }
         ll pos=n;
         for(int j=; j<sum; j++)
         {
             pos*=n;
         }
         num+=pos*ans;
     }
     else
     {
         num+=ans*n;
     }
     i=r;
     if(s[l]=='-')
     {
         num*=-;
     }
     return num;
 }
 int main()
 {
     while(~scanf("%d",&n))
     {
         ll x=;
         scanf("%s",s);
         int len=strlen(s);
         if((s[]>=''&&s[]<='')||s[]=='X')
         {
             string s1="";
             int i=;
             int pos=;
             int flag=;
             for(i=; s[i]!='+'&&s[i]!='-'&&i<len; i++)
             {
                 s1+=s[i];
                 if(s[i]=='X')
                 {
                     flag=;
                     pos=i;
                 }
             }
             if(flag)
             {
                 x+=Solve(s1,pos);
                 flag=;
             }
             else
             {
                 ll ans=;
                 for(int j=; j<s1.length(); j++)
                 {
                     ans*=;
                     ans+=(s1[j]-'');
                 }
                 x+=ans;
             }
             for(int j=i; j<len;)
             {
                 if(s[j]=='-'||s[j]=='+')
                 {
                     string s2="";
                     s2+=s[j];
                     j++;
                     int ans=;
                     while(s[j]!='-'&&s[j]!='+'&&j<len)
                     {
                         s2+=s[j];
                         ans++;
                         if(s[j]=='X')
                         {
                             pos=ans;
                             flag=;
                         }
                         //cout<<s[j]<<endl;
                         j++;
                     }
                     if(flag)
                     {
                         x+=Solve(s2,pos);
                         flag=;
                     }
                     else
                     {
                         ll ans=;
                         for(int j=; j<s2.length(); j++)
                         {
                             ans*=;
                             ans+=(s2[j]-'');
                         }
                         if(s2[]=='-')
                         {
                             ans*=-;
                         }
                         x+=ans;
                     }
                     flag=;
                 }
             }
             cout<<x<<endl;
         }
         else
         {
             int flag=;
             int pos=;
             string s3="";
             s3+=s[];
             int i;
             for(i=; s[i]!='-'&&s[i]!='+'&&i<len; i++)
             {
                 s3+=s[i];
                 if(s[i]=='X')
                 {
                     flag=;
                     pos=i;
                 }
             }
             if(flag)
             {
                 x+=Solve(s3,pos);
                 flag=;
             }
             else
             {
                 ll ans=;
                 for(int j=; j<s3.length(); j++)
                 {
                     ans*=;
                     ans+=(s3[j]-'');
                 }
                 if(s3[]=='-')
                 {
                     ans*=-;
                 }
                 x+=ans;
             }
             flag=;
             for(int j=i; j<len;)
             {
                 if(s[j]=='-'||s[j]=='+')
                 {
                     string s2="";
                     s2+=s[j];
                     j++;
                     int ans=;
                     while(s[j]!='-'&&s[j]!='+'&&j<len)
                     {
                         s2+=s[j];
                         ans++;
                         if(s[j]=='X')
                         {
                             pos=ans;
                             flag=;
                         }
                         //cout<<s[j]<<endl;
                         j++;
                     }
                     if(flag)
                     {
                         x+=Solve(s2,pos);
                         flag=;
                     }
                     else
                     {
                         ll ans=;
                         for(int j=; j<s2.length(); j++)
                         {
                             ans*=;
                             ans+=(s2[j]-'');
                         }
                         if(s2[]=='-')
                         {
                             ans*=-;
                         }
                         x+=ans;
                     }
                     flag=;
                 }
             }
             cout<<x<<endl;
         }
     }
     return ;
 }