poj-1686-Lazy Math Instructor(stack)

来源：互联网发布：天干地支年算法编辑：程序博客网时间：2024/05/17 07:00
题目地址

http://poj.org/problem?id=1686
Code

#include <stdio.h>#include <iostream>#include <stdlib.h>#include <string.h>#include <queue>#include <stack>#include <string>#include <map>#include <sstream>#include <vector>#include <math.h>#include <algorithm>#define INF 0x3fffffff#define N 1005#define p(x) cout << (x) << endl;int dx[4] = {0, 0, 1, -1};int dy[4] = {1, -1, 0, 0};using namespace std;typedef long long LL;int a[N];int init[N];int C(char a, char b){    int r ;    switch(b){        case '+':        case '-':            if(a=='(' || a=='#')                r = -1 ;    //入栈            else                r = 1 ;     //计算            break ;        case '*':        case '/':            if(a=='*' || a=='/' || a==')')                r =1 ;      //计算            else                r = -1 ;    //入栈            break ;        case '(':            if(a == ')'){                printf("error!\n");                exit(1) ;            }            else{                r = -1 ;    //入栈            }            break ;        case ')':            if(a == '(')                r = 0 ;            else                r = 1  ;            break ;        case '#':            if(a=='#')                r = 0 ;            else                r = 1 ;            break ;    }    return r ;}int cal(int a, int b , char c){    int res ;    switch(c){        case '+':   res = a + b ;   break ;        case '-':   res = a - b ; break ;        case '*':   res = a * b ; break ;        case '/':   res = a / b ; break ;    }    //printf("%d = %d %c %d\n", res, a, c, b);    return res ;}int hand(string s) {    map<char, int> mp;    for (int i = 0; i <= 9; i++) {        mp['0'+i] = i;    }    int v = 1;    for (int i = 0; i < s.size(); i++) {        if (s[i] == ' ' || s[i] == '\t') {            continue;        }        if (s[i] == '(' || s[i] == ')' || s[i] == '+' || s[i] == '-' || s[i] == '*') {            continue;        }        if ('0' <= s[i] && s[i] <= '9') {            continue;        }        // not same with 0~9        if (mp[s[i]] == 0) {            mp[s[i]] = s[i] - 'A' + 10;        }    }    //p(mp['a'])    //p(mp['b'])    //p(mp['c'])    //p(s)    stack<char> f; f.push('#');    stack<int> d;    int x, y;    for (int i = 0; i < s.size(); i++) {        if (s[i] == ' ' || s[i] == '\t') {            continue;        }        char pre = f.top();        char c = s[i];        switch (c) {            case '(' :            case ')' :            case '+' :            case '-' :            case '*' :            case '#' :                switch(C(pre, c)){                    case 0:                        f.pop();                        break ;                    case -1 :                        f.push(c);                        break ;                    case 1 :                        i--;                        f.pop();                        int a = d.top(); d.pop();                        int b = d.top(); d.pop();                        d.push(cal(b, a, pre));                        break ;                }                break;            default :  d.push(mp[c]); break;        }    }    return d.top();}int main() {#ifndef ONLINE_JUDGE    freopen("in", "r", stdin);#else    //#endif    int n;    cin >> n;    getchar();    for (int i = 0; i < n; i++) {        string s1, s2;        getline(cin, s1);        getline(cin, s2);        s1 += "#";        s2 += "#";        int ans1 = hand(s1);        int ans2 = hand(s2);        //cout << ans1 << " " << ans2 << endl;        if (ans1 == ans2) {            cout << "YES" << endl;        } else {            cout << "NO" << endl;        }    }    return 0;}
参考

http://blog.csdn.net/ivan_zjj/article/details/7354271
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