C :

#include <stdio.h>
#include <stdlib.h>
#define INF 0x7fffffff
/* run this program using the console pauser or add your own getch, system("pause") or input loop */

int main(int argc, char *argv[]) {
	int n;
	while(scanf("%d",&n)!=EOF){
		
		while(n--){
			int s,g;
			scanf("%d%d",&s,&g);
			g-=s;
			int w[550],v[550];
			int number;
			scanf("%d",&number);
			int i,j;
			int dp[10050]; 
			for(i=0;i<number;i++){
				scanf("%d%d",&v[i],&w[i]);
			}
			for(i=0;i<=g;i++){
				dp[i]=INF;
			}
			dp[0]=0;
			for(i=0;i<number;i++){
				for(j=w[i];j<=g;j++){
					if(dp[j-w[i]]!=INF)
					dp[j]=dp[j]<(dp[j-w[i]]+v[i])?dp[j]:(dp[j-w[i]]+v[i]);
				}
			}
			if(dp[g]!=INF)
			printf("The minimum amount of money in the piggy-bank is %d.\n",dp[g]);
			else
			printf("This is impossible.\n");
		}
	}
	return 0;
}

C++ :

#include <stdio.h>
int c[555][10001];
void run()
{
	int i,j,a[666],b[666],e,f,n,k;
	scanf("%d%d%d",&e,&f,&n);
	f-=e;
	for(i=1;i<=n;i++)
		scanf("%d%d",&a[i],&b[i]);
	for(i=1;i<=n;i++)
		for(j=0;j<=f;j++)
			c[i][j]=1000000000;
	c[1][0]=0;
	for(i=1;i<=n;i++)
		for(j=0;j<=f;j++)
		{
			k=1000000000;
			if(j>=b[i])
				k=c[i][j-b[i]]+a[i];
			if(i>1)
				if(k>c[i-1][j])
					k=c[i-1][j];
			if(c[i][j]>k)
				c[i][j]=k;
		}
	if(c[n][f]==1000000000)
		printf("This is impossible.\n");
	else
		printf("The minimum amount of money in the piggy-bank is %d.\n",c[n][f]);
}
int main()
{
	int t;
	scanf("%d",&t);
	while(t!=0)
	{
		t--;
		run();
	}
	return 0;
}