也是母函数的题。。。套模板吧。。。
/*******************************************************************************
# Author : Neo Fung
# Email : neosfung@gmail.com
# Last modified: 2012-07-04 19:10
# Filename: HDU2152 Fruit.cpp
# Description :
******************************************************************************/
#ifdef _MSC_VER
#define DEBUG
#define _CRT_SECURE_NO_DEPRECATE
#endif
#include <fstream>
#include <stdio.h>
#include <iostream>
#include <string.h>
#include <string>
#include <limits.h>
#include <algorithm>
#include <math.h>
#include <numeric>
#include <functional>
#include <ctype.h>
using namespace std;
const int kMAX=100100;
const double kEPS=10E-6;
int ans[kMAX],tans[kMAX];
int a[kMAX],b[kMAX];
int main(void)
{
#ifdef DEBUG
freopen("../stdin.txt","r",stdin);
freopen("../stdout.txt","w",stdout);
#endif
int n,m;
while(~scanf("%d%d",&n,&m) )
{
for(int i=0;i<n;++i)
scanf("%d%d",&a[i],&b[i]);
memset(ans,0,sizeof(ans));
memset(tans,0,sizeof(tans));
ans[0]=1;
for(int i=0;i<n;++i)
{
for(int j=0;j<=m;++j)
if(ans[j])
{
for(int k=a[i];k+j<=m && k<=b[i];++k)
tans[k+j]+=ans[j];
}
memcpy(ans,tans,sizeof(ans));
memset(tans,0,sizeof(tans));
}
printf("%d\n",ans[m]);
}
return 0;
}