pat 表达式转换

来源：互联网发布：猜你喜欢人工智能编辑：程序博客网时间：2024/06/05 10:19

好多细节多找点数据输入输出看看自己哪里有不足就行了吧

#include<bits/stdc++.h>using namespace std;string str;int flag=1;int f=1;bool op(int i,char c){if(str[i-1]>'9'||str[i-1]<'0'&&(str[i-1]!=')'))return 0;if(c=='+'||c=='-'||c=='*'||c=='/')return true;return false;}bool out(int i,char c){if(c>='0'&&c<='9')return 1;if(c=='.')return 1;if(c=='-'){ if(i==0) return 1; else if(str[i-1]>='0'&&str[i-1]<='9'||str[i-1]==')') return 0; return 1;    }    return 0;}map<char,int > m;void solve(int l,int r){stack<char> s;for(int i=l;i<=r;i++){if(out(i,str[i])){if(flag==1||f){ flag=0; f=1; cout<<str[i];    }else{ f=1; cout<<' '<<str[i];   }    }else if(op(i,str[i])){f=0;if(!s.empty()){ while(m[str[i]]<=m[s.top()]) {  cout<<' '<<s.top();  f=0;  s.pop();  if(s.empty())  break;      }    } s.push(str[i]);}else if(str[i]=='('){stack<char> q; int j=i+1;q.push('(');while(!q.empty()){if(str[j]==')')q.pop();else if(str[j]=='(')q.push('(');j++;}solve(i+1,j-2);i=j-1;}}while(!s.empty()){f=0;cout<<' '<<s.top();s.pop();}}int main(){m['+']=1;m['-']=1;m['*']=2;m['/']=2;cin>>str;solve(0,str.length());}

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