hdu Integer Inquiry 解题报告

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1047

题目意思：就是求大整数加法。有多个案例，每个案例之间要输出一个空格。

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstdlib>
 4 #include <cstring>
 5 using namespace std;
 6 
 7 const int maxn = 10000 + 10;
 8 char t[maxn];
 9 int s[maxn], ans[maxn];
10 
11 int main()
12 {
13     int l1, l2, n, i, j, l, len, num;
14     scanf("%d", &n);
15     while (n--)
16     {
17         num = 0;
18         memset(ans, 0, sizeof(ans));
19         while (cin >> t && strcmp(t, "0"))
20         {
21             memset(s, 0, sizeof(s));
22             l1 = strlen(t);
23             for (i = 0; i < l1; i++)
24                 s[i] = t[l1-i-1] - '0';
25             num++;
26             if (num == 1)
27             {
28                 for (i = 0; i < l1; i++)
29                     ans[i] = s[i];
30                 l2 = l1;
31             }
32             else
33             {
34                 len = max(l1, l2);  // l1:s[i] l2:ans[i]
35                 l = min(l1, l2);
36                 int sum, c = 0;
37                 for (i = 0; i < len; i++)
38                 {
39                     if (i < l)
40                     {
41                         sum = s[i] + ans[i] + c;
42                         ans[i] = sum % 10;
43                         c = (sum > 9 ?  1 : 0);
44                     }
45                     else
46                     {
47                         if (l1 == len)
48                             sum = s[i] + c;
49                         else
50                             sum  = ans[i] + c;
51                         ans[i] = sum % 10;
52                         c = (sum > 9 ?  1 : 0);
53                     }
54                 }
55                 if (c == 1 && i == len)
56                 {
57                     ans[len] = 1;
58                     l2 = len + 1;
59                 }
60                 else
61                     l2 = len;   // 关键之处！！！！之前不记得更新错了好多次！！！
62             }
63         }
64         if (!num)
65             printf("0");
66         else
67         {
68             for (i = maxn-1; i >= 0; i--)
69             {
70                 if (ans[i])
71                     break;
72             }
73             for ( ; i >= 0; i--)
74                 printf("%d", ans[i]);
75         }
76         printf("\n");
77         if (n)
78             cout << endl;
79     }
80     return 0;
81 }

 

　　忽略格式问题，借鉴了别人的写法

   

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstdlib>
 4 #include <cstring>
 5 using namespace std;
 6 
 7 const int maxn = 1e5 + 10;
 8 char t[maxn];
 9 int num[maxn];
10 
11 void add(char s[])
12 {
13     int z = 0;
14     int len = strlen(s);
15     for (int i = len-1; i >= 0; i--)
16     {
17         num[z] += (s[i] - '0');
18         num[z+1] += num[z] / 10;
19         num[z] %= 10;
20         z++;
21     }
22 }
23 
24 int main()
25 {
26     int i, ok = 0;
27     memset(num, 0, sizeof(num));
28     while (scanf("%s", t) != EOF && strcmp(t, "0"))
29         add(t);
30     for (i = maxn; i >= 0; i--)
31     {
32         if (num[i])
33         {
34             ok = 1;
35             break;
36         }
37     }
38     for ( ; i >= 0 && ok; i--)
39          printf("%d", num[i]);
40     if (!ok)
41         printf("0");
42     printf("\n");
43     return 0;
44 }

 

posted @ 2014-04-03 22:06  windysai  阅读(211)  评论(0)  编辑  收藏  举报