数字在排序数组中出现的次数

题目描述：

统计一个数字在排序数组中出现的次数。

poj 网址：http://ac.jobdu.com/problem.php?pid=1349

可以AC的代码，看主要函数就行了，该poj系统的输入输出做的太烂，我用cin不支持，老报超时的错误

int findFirstPos(int *arr,int target,int start,int end, int len)
{
while(start<end)
{
int mid=(end-start)/2+start;
if(arr[mid]==target)
{
if(mid==0 || (mid>0 && arr[mid-1]!=target))
{
return mid;
}else
{
end=mid-1;
}
}else if(arr[mid]>target)
{
end=mid-1;
}else
{
start=mid+1;
}
}
if(arr[start]==target)
{
return start;
}else
{
return -1;
}

}
int findLastPos(int *arr, int target,int start, int end,int len)
{
while(start<end)
{
int mid=(end-start)/2+start;
if(arr[mid]==target)
{
if(mid==len-1 || (mid<len-1 && arr[mid+1]!=target))
{
return mid;
}else
{
start=mid+1;
}
}else if(arr[mid]>target)
{
end=mid-1;
}else
{
start=mid+1;
}
}
if(arr[start]==target)
{
return start;
}else
{
return -1;
}
}
int timesForSequence(int *arr,int target,int start,int end,int len)
{
int firstPos=findFirstPos(arr,target,start,end,len);
int lastPos=findLastPos(arr,target, start, end,len);
if(firstPos!=-1 && lastPos!=-1)
{
return lastPos-firstPos+1;
}
return 0;
}

int n,m,k,a[1000000];
inline void read(int &data)
{
char ch = getchar();
while (ch < '0' || ch > '9')
ch = getchar();
data = 0;
do{
data = data*10 + ch-'0';
ch = getchar();
}while (ch >= '0' && ch <= '9');
}
int main(int argc, const char * argv[])
{
while(scanf("%d",&n)!=EOF)
{
for(int i=0;i<n;i++)
{
read(a[i]);
}
read(m);
for(int j=0;j<m;j++)
{
read(k);
cout<<timesForSequence(a,k,0,n-1,n)<<endl;
}
}

return 0;
}