POJ 1503 Integer Inquiry

http://poj.org/problem?id=1503

题意：
给出n个数，计算和。

思路：

基础的大整数加法题。

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <algorithm>
 5 #include <cmath>
 6 #include<vector>
 7 using namespace std;
 8
 9 const int maxn = 100 + 5;
10
11 char s[maxn][maxn];
12 int num[maxn][maxn];
13 int ans[maxn];
14 int max_len;
15 int n;
16
17 int add()
18 {
19     int i;
20     int t = 0;
21     for (i = 0; i < max_len; i++)
22     {
23         int k = 0;
24         for (int j = 0; j < n; j++)
25         {
26             k += num[j][i];
27         }
28         k += t;
29         ans[i] = k % 10;
30         t = k / 10;
31     }
32     while (t)
33     {
34         ans[i++] = t % 10;
35         t /= 10;
36     }
37     return i;
38 }
39
40 int main()
41 {
42     //freopen("D:\\txt.txt", "r", stdin);
43     n = 0;
44     max_len = 0;
45     memset(num, 0, sizeof(num));
46     while (gets(s[n]))
47     {
48         if (!strcmp(s[n], "0"))  break;
49         int len = strlen(s[n]);
50         max_len = max(max_len, len);
51         for (int i = len - 1; i >= 0; i--)
52             num[n][len - 1 - i] = s[n][i] - ‘0‘;
53         n++;
54     }
55     int cnt = add();
56     for (int i = cnt - 1; i >= 0;i--)
57         printf("%d", ans[i]);
58     printf("\n");
59     return 0;
60 }