【NOIP2018提高组D1T1】铺设道路

这题不用讲了吧，一遍扫直接过

#include<cstdio>
using namespace std;
int n,a[100010],ans=0;

inline int read()
{
	int x=0; char c=getchar();
	while (c<'0' || c>'9') c=getchar();
	while (c>='0' && c<='9') x=x*10+c-48,c=getchar();
	return x;
}

int main()
{
	freopen("road.in","r",stdin);
	freopen("road.out","w",stdout);
	n=read();
	ans=a[1]=read();
	for (int i=2;i<=n;i++)
	{
		a[i]=read();
		if (a[i]>a[i-1]) ans+=a[i]-a[i-1];
	}
	printf("%d
",ans);
	return 0;
}