hdu 5059 Help him

Help him

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)

Total Submission(s): 480 Accepted Submission(s): 119



Problem Description

As you know, when you want to hack someone's program, you must submit your test data. However sometimes you will submit invalid data, so we need a data checker to check your data. Now small W has prepared a problem for BC, but he is too busy to write the data
checker. Please help him to write a data check which judges whether the input is an integer ranged from a to b (inclusive).

Note: a string represents a valid integer when it follows below rules.

1. When it represents a non-negative integer, it contains only digits without leading zeros.

2. When it represents a negative integer, it contains exact one negative sign ('-') followed by digits without leading zeros and there are no characters before '-'.

3. Otherwise it is not a valid integer.

Input

Multi test cases (about 100), every case occupies two lines, the first line contain a string which represents the input string, then second line contains a and b separated by space. Process to the end of file.

Length of string is no more than 100.

The string may contain any characters other than '\n','\r'.

-1000000000$\leq a \leq b \leq 1000000000$

Output

For each case output "YES" (without quote) when the string is an integer ranged from a to b, otherwise output "NO" (without quote).

Sample Input

10
-100 100
1a0
-100 100

Sample Output

YES
NO

Source

BestCoder Round #12

题解及代码：

题意非常easy，给一个字符串。和一个区间，看这个字符串是否能构成一个合法的整数。而且其值是否在这个区间内（注意-0为非法数据）。

首先直接排除-和-0的情况。然后推断前导0的情况，再推断0-9以外字符的情况，接着看其长度是否大于12，最后把它转化成整数，推断大小。

#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <map>
using namespace std;
typedef long long ll;

bool judge(char s[],ll a,ll b)
{
ll num=0,d=1,i=0;
int len=strlen(s),k=0;
if(s[0]=='-') d=-1,k++;
if(k==len||s[0]=='-'&&s[k]=='0') return false;
for(i=k;i<len-1;i++)
if(s[i]!='0') break;

if(i!=k) return false;
for(int i=k;i<len;i++)
if(s[i]<'0'||s[i]>'9') return false;

for(int i=k;i<len;i++)
{
num=num*10+s[i]-'0';
if(i-k>11) return false;
}
//printf("%I64d\n",num*d);
if(num*d<a||num*d>b)  return false;
return true;
}

int main()
{
ll a,b;
char s[110];
while(gets(s)!=NULL)
{
scanf("%I64d%I64d",&a,&b);
if(a>b) swap(a,b);

if(judge(s,a,b)) printf("YES\n");
else printf("NO\n");
getchar();
}
return 0;
}