nyoj305

来源：互联网发布：阿里云域名怎么绑定ip 编辑：程序博客网时间：2024/06/05 10:41

题意：表达式求值
思路：栈的运用。
AC代码：

#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>#include <string>#include <stack>#include <queue>using namespace std;const int maxn=500;char ch[maxn];void calc(char *ch){    stack<int>s;   //数字    stack<char>ss;  // 运算符号    stack<char>sss; //比较符号    int len=strlen(ch);    for(int i=0; i<len; i++){        if(ch[i]==',') continue;        if(ch[i]=='m') continue;        if(ch[i]=='a' && ch[i+1]=='d') {            sss.push(ch[i+1]); i+=2;        }else if(ch[i]=='i'){            sss.push(ch[i]); i+=1;        }else if(ch[i]=='a' && ch[i+1]=='x'){            sss.push(ch[i]); i+=1;        }        else if(ch[i]=='('){            ss.push(ch[i]);        }        else if(ch[i]==')'){            int xx=s.top();            s.pop();            int yy=s.top();            s.pop();            if(sss.top()=='i'){                s.push(min(xx,yy));            }else if(sss.top()=='d'){                s.push(xx+yy);            }else if(sss.top()=='a') {                s.push(max(xx,yy));            }            sss.pop();            ss.pop();        }        else if(ch[i]>='0' && ch[i]<='9'){            int xx=0;            while(ch[i]>='0' && ch[i]<='9'){                xx=xx*10+ch[i]-'0'; i++;            }            i=i-1;            s.push(xx);        }    }    printf("%d\n",s.top());}int main(){    int t;    scanf("%d",&t);    while(t--){        scanf("%s",ch);        calc(ch);    }    return 0;}

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