Poj 3982 序列

 1 #include <iostream>
 2 #include <string>
 3 
 4 using namespace std;
 5 
 6 const int Num = 100;
 7 
 8 string sum(string s1,string s2)
 9 {
10     if(s1.length()<s2.length())
11     {
12         string temp=s1;
13         s1=s2;
14         s2=temp;
15     }
16     int i,j;
17     for(i=s1.length()-1,j=s2.length()-1;i>=0;i--,j--)
18     {
19         s1[i]=char(s1[i]+(j>=0?s2[j]-‘0‘:0));   //注意细节
20         if(s1[i]-‘0‘>=10)
21         {
22             s1[i]=char((s1[i]-‘0‘)%10+‘0‘);
23             if(i) s1[i-1]++;
24             else s1=‘1‘+s1;
25         }
26     }
27     return s1;
28 }
29 
30 int main()
31 {
32     //freopen("D://input.txt","r",stdin);
33 
34     int i;
35 
36     string str0,str1,str2,str3;
37 
38     while(cin >> str0 >> str1 >> str2)
39     {
40         //cout << str0 << endl;
41         //cout << str1 << endl;
42         //cout << str2 << endl;
43 
44         i = Num - 3;
45         while(i--)
46         {
47             str3 = sum(str0,str1);
48             str3 = sum(str3,str2);
49             str0 = str1;
50             str1 = str2;
51             str2 = str3;
52         }
53 
54         cout << str3 << endl;
55 
56     }
57 
58     return 0;
59 }