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问题是求出斐波那契数列的第n个，这里要用大数加法预处理，然后就可以了

代码：

 1 #include <iostream>
 2 #include <sstream>
 3 #include <cstdio>
 4 #include <climits>
 5 #include <cstring>
 6 #include <cstdlib>
 7 #include <string>
 8 #include <stack>
 9 #include <map>
10 #include <cmath>
11 #include <vector>
12 #include <queue>
13 #include <algorithm>
14 #define esp 1e-6
15 #define pi acos(-1.0)
16 #define pb push_back
17 #define lson l, m, rt<<1
18 #define rson m+1, r, rt<<1|1
19 #define mp(a, b) make_pair((a), (b))
20 #define in  freopen("in.txt", "r", stdin);
21 #define out freopen("out.txt", "w", stdout);
22 #define print(a) printf("%d\n",(a));
23 #define bug puts("********))))))");
24 #define stop  system("pause");
25 #define Rep(i, c) for(__typeof(c.end()) i = c.begin(); i != c.end(); i++)
26 #define inf 0x0f0f0f0f
27 
28 using namespace std;
29 typedef long long  LL;
30 typedef vector<int> VI;
31 typedef pair<int, int> pii;
32 typedef vector<pii> VII;
33 typedef vector<pii, int> VIII;
34 typedef VI:: iterator IT;
35 struct BigInt
36 {
37     int len;
38     int f[1100];
39     void Init(int n)
40     {
41         memset(f, 0, sizeof(f));
42         len = 0;
43         while(n)
44         {
45             f[len] = n % 10;
46             n /= 10;
47             len++;
48         }
49 
50         if(len > 0)
51         len--;
52     }
53     BigInt operator + (const BigInt &a)const
54     {
55         int carry = 0;
56         BigInt c;
57         c.Init(0);
58        int i;
59         for(i = 0; i <= max(a.len, len); i++)
60         {
61             carry = carry + f[i] + a.f[i];
62             c.f[i] = carry%10;
63             carry /= 10;
64         }
65         if(carry == 0)
66             return         c.len = i - 1, c;
67         while(carry)
68         {
69             c.f[i] = carry%10;
70             carry /= 10;
71             i++;
72         }
73         c.len = i-1;
74         return c;
75     }
76 };
77 
78 BigInt fi[11000];
79 int main(void)
80 {
81     fi[1].Init(1);
82     fi[2].Init(1);
83     for(int i = 3; i <= 2000; i++)
84         fi[i] = fi[i-2] + fi[i-1];
85     int t;
86     while(scanf("%d", &t), t)
87     {
88         for(int i = fi[t].len; i >= 0; i--)
89             printf("%d", fi[t].f[i]);
90         puts("");
91     }
92     return 0;
93 }

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