HDU 1284 钱币兑换问题 母函数 or 完全背包

i相信知道做前面那个后这个应该很水了

#include<stdio.h>
int m1[40000],m2[40000];
void chart(  )
{
	for( int i = 0 ; i <=32780; ++i )
	{
		m1[i] = 1;
		m2[i] = 0;
	}
	for( int i = 2; i <= 3;++i )
	{
		for( int j = 0; j <= 32780; ++j )
			for( int k = 0; k + j <= 32780; k += i )
				m2[j + k] += m1[j];
		for( int j = 0; j <= 32780; ++j )
		{
			m1[j] = m2[j];
			m2[j] = 0;
		}
	}
}
int main( )
{
	chart( );
	int n;
	while( scanf( "%d",&n ) != EOF )
		printf( "%d\n",m1[n] );
	return 0;
} 

用完全背包做

#include<stdio.h>
#include<string.h>
int coin[4] = { 0 , 1, 2 , 3},dp[32780],n;
void DP(  )
{
     memset( dp,0,sizeof( dp ) );
     dp[0] = 1;
     for( int i = 1; i <= 3; ++i )
          for( int j = coin[i]; j <= n; ++j )
               dp[j] += dp[j-coin[i]];
     printf( "%d\n",dp[n] );
 }
int main( )
{
    while( scanf( "%d",&n ) != EOF )
           DP(  );
    return 0;
}