表达式计算系列【未完】

 1 #include <iostream>
 2 #include <string>
 3 using namespace std;
 4 
 5 string ans(1501, ‘0‘);
 6 
 7 void pl(const string& s, size_t& l)
 8 {
 9     int jw = 0;
10     for (size_t i = 0; i<l; ++i)
11     {
12         int x = (ans[i] - ‘0‘) + (s[i] - ‘0‘) + jw;
13         jw = 0;
14         if (x>9)
15         {
16             ans[i] = (x - 10) + ‘0‘;
17             ++jw;
18         }
19         else
20             ans[i] = x + ‘0‘;
21     }
22     while (jw)
23     {
24         int x = ans[l] - ‘0‘ + jw;
25         jw = 0;
26         if (x>9)
27         {
28             ++jw;
29             ans[l] = (x - 10) + ‘0‘;
30             ++l;
31         }
32         else
33             ans[l] = x + ‘0‘;
34     }
35 }
36 inline size_t max(const size_t& a, const size_t& b)
37 {
38     return a > b ? a : b;
39 }
40 int main()
41 {
42     unsigned int c;
43     string cc;
44     cc.clear();
45     size_t len = 0;
46     while ((c=getchar())!=‘\n‘)
47     {
48         if (c != ‘+‘)
49             cc += c;
50         else
51         {
52             size_t p = cc.size();
53             for (size_t i = 0; i<p / 2; ++i)
54             {
55                 unsigned int temp = cc[i];
56                 cc[i] = cc[p - i - 1];
57                 cc[p - i - 1] = temp;
58             }
59             pl(cc, p);
60             len = max(len,p);
61             cc.clear();
62         }
63     }
64     size_t p = cc.size();
65     for (size_t i = 0; i<p / 2; ++i)
66     {
67         unsigned int temp = cc[i];
68         cc[i] = cc[p - i - 1];
69         cc[p - i - 1] = temp;
70     }
71     pl(cc, p);
72     for (string::reverse_iterator i = ans.rend() - len; i != ans.rend(); ++i)
73         cout << *i;
74     cout << endl;
75     return 0;
76 }

 1 #include<iostream>
 2 #include<cstring>
 3 #include<cstdio>
 4 #include<algorithm>
 5 using namespace std;
 6 int ans[1501],num[1501],ansl=0;
 7 string str1;
 8 void get(int x)
 9 {
10     for(int i=0;i<x;i++)
11     {
12         ans[i]+=num[i];
13     }
14     ansl=max(ansl,x-1);
15     for(int i=0;i<ansl;i++)
16     {
17         ans[i+1]+=ans[i]/10;
18         ans[i]%=10;
19     }
20     if(ans[ansl]>0)++ansl;
21 }
22 void add()
23 {
24     int i=0;
25     int x=str1.length();
26     while(x--)
27     {
28         if(str1[x]==‘+‘)
29         {
30            get(i);
31            i=0;
32            memset(num,0,sizeof(num));
33            }
34         else num[i++]=str1[x]-48;
35     }
36     get(i);
37 }
38 int main()
39 {
40    cin>>str1;
41    add();
42    for(int i=ansl-1;i>=0;i--)
43       cout<<ans[i];
44    return 0;    
45 }