2393.txt

北大ACM题目例程 详细的解答过程 程序实现 算法分析

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>
#define NMAX 1000
#define HMAX 30
unsigned int S,N;
int main()
{

#if _DEBUG	
	freopen("in.txt","r",stdin);
	freopen("out.txt","w",stdout);
#endif
	scanf("%d%d",&N,&S);
	unsigned int i;
	__int64 max=0;
	unsigned int a,b;
	scanf("%d%d",&a,&b);
	max+=a*b;
	unsigned int t=a;
	for(i=2;i<=N;i++)
	{
		scanf("%d%d",&a,&b);
		if(a>t+S)
			a=t+S;
		max+=a*b;
		t=a;
	}
	printf("%I64d",max);
	
#if _DEBUG
	fclose(stdin);
	fclose(stdout);
#endif
	return 1;
}