先前看是英文题就没打算做，可是看看用例之后，大概知道这个题的意思：输入一行字符串，判断从a到z之间每个字母出现的次数，完全水题一个，果断做了,一次性通过。
描述
Ignatius is doing his homework now. The teacher gives him some articles and asks him to tell how many times each letter appears.
It's really easy, isn't it? So come on and AC ME.
输入
Each article consists of just one line, and all the letters are in lowercase. You just have to count the number of each letter, so do not pay attention to other characters. The length of article is at most 100000. Process to the end of file.
Note: the problem has multi-cases, and you may use "while(gets(buf)){...}" to process to the end of file.
输出
For each article, you have to tell how many times each letter appears. The output format is like "X:N".
Output a blank line after each test case. More details in sample output.
样例输入
hello, this is my first acm contest!
work hard for hdu acm.
样例输出
a:1
b:0
c:2
d:0
e:2
f:1
g:0
h:2
i:3
j:0
k:0
l:2
m:2
n:1
o:2
p:0
q:0
r:1
s:4
t:4
u:0
v:0
w:0
x:0
y:1
z:0
a:2
b:0
c:1
d:2
e:0
f:1
g:0
h:2
i:0
j:0
k:1
l:0
m:1
n:0
o:2
p:0
q:0
r:3
s:0
t:0
u:1
v:0
w:1
x:0
y:0
z:0
#include<iostream>
#include<cstring>
#include<stdio.h>
using namespace std;
int b[40];
char a[1000000];
int main()
{
while(gets(a))
{
memset(b,0,sizeof(b));
int l=strlen(a);
for(int i=0;i<l;i++)
if(a[i]>='a'&&a[i]<='z'){
b[a[i]-'a']++;
}
int k=0;
for(int a=97;a<123;a++)
cout<<char(a)<<":"<<b[k++]<<endl;
cout<<endl;
}
return 0;
}