BUAA 623 Chem is Try！

http://oj55.bianchengla.com/problem/623/
　　好久没写过题解了，昨天做了一道挺恶心的题目，贴一下代码上来。看了一下提交状况，好像我的代码挺短的了，至少我找不到比我短的代码。RE1，AC。
代码如下：
  1 #include <cctype>
  2 #include <cstdio>
  3 #include <cstring>
  4 #include <map>
  5 #include <string>
  6 #include <iostream>
  7 #include <algorithm>
  8 
  9 using namespace std;
 10 
 11 const int N = 111111;
 12 char buf[N], *p[2];
 13 typedef long long LL;
 14 typedef map<string, LL> MSL;
 15 #define x first
 16 #define y second
 17 
 18 string get_s(int x) {
 19     string ret = "";
 20     ret += *(p[x]++);
 21     while (islower(*p[x])) ret += *p[x], p[x]++;
 22     return ret;
 23 }
 24 
 25 int get_d(int x) {
 26     int ret = 0;
 27     while (isdigit(*p[x])) ret = ret * 10 + *p[x] - '0', p[x]++;
 28     return ret;
 29 }
 30 
 31 MSL merge(MSL a, MSL b) {
 32     MSL c;
 33     for (MSL::iterator mi = a.begin(); mi != a.end(); mi++) c[mi->x] += mi->y;
 34     for (MSL::iterator mi = b.begin(); mi != b.end(); mi++) c[mi->x] += mi->y;
 35     return c;
 36 }
 37 
 38 
 39 void print(MSL &a) { for (MSL::iterator mi = a.begin(); mi != a.end(); mi++) cout << mi->x << '~' << mi->y << ' '; cout << endl; }
 40 void multiply(MSL &a, LL p) { for (MSL::iterator mi = a.begin(); mi != a.end(); mi++) mi->y *= p; }
 41 
 42 MSL dfs(int x, char end) {
 43     MSL cur;
 44     //cout << x << ' ' << p[x] << endl;
 45     while (*p[x] && *p[x] != end && *p[x] != ')') {
 46         //cout << x << ' ' << *p[x] << endl;
 47         if (*p[x] == '+') { p[x]++; continue; }
 48         if (isdigit(*p[x])) {
 49             int t = get_d(x);
 50             MSL tmp = dfs(x, '+');
 51             multiply(tmp, t);
 52             cur = merge(cur, tmp);
 53         } else {
 54             if (*p[x] == '(') {
 55                 p[x]++; MSL tmp = dfs(x, ')');
 56                 if (*p[x] == ')') p[x]++;
 57                 if (isdigit(*p[x])) multiply(tmp, get_d(x));
 58                 cur = merge(cur, tmp);
 59             } else {
 60                 string s = get_s(x);
 61                 if (isdigit(*p[x])) cur[s] += get_d(x);
 62                 else cur[s]++;
 63             }
 64         }
 65     }
 66     return cur;
 67 }
 68 
 69 int main() {
 70     //freopen("in", "r", stdin);
 71     while (~scanf("%s", buf)) {
 72         p[0] = p[1] = buf;
 73         while (*p[1] != '=') p[1]++; *(p[1]++) = 0;
 74         MSL ans1, ans2, tmp;
 75         while (1) {
 76             tmp = dfs(0, '+');
 77             ans1 = merge(ans1, tmp);
 78             if (*p[0] == 0) break;
 79             p[0]++;
 80             //cout << p[0] << endl;
 81         }
 82         while (1) {
 83             tmp = dfs(1, '+');
 84             ans2 = merge(ans2, tmp);
 85             if (*p[1] == 0) break;
 86             p[1]++;
 87             //cout << p[1] << endl;
 88         }
 89         MSL::iterator m1 = ans1.begin(), m2 = ans2.begin();
 90         //print(ans1); print(ans2);
 91         while (1) {
 92             if (m1 == ans1.end()) break;
 93             if (m2 == ans2.end()) break;
 94             if (*m1 != *m2) break;
 95             m1++, m2++;
 96         }
 97         m1 == ans1.end() && m2 == ans2.end() ? puts("YES") : puts("NO");
 98     }
 99     return 0;
100 }
View Code
——written by Lyon