代码

#include<cstdio>
#define N 100000

using namespace std;

#define max(a, b) ((a) < (b) ? (b) : (a))

void read(int &x)
{
	char ch=getchar(); x=0;
	while (ch<'0'||ch>'9') ch=getchar();
	while (ch>='0'&&ch<='9') x=(x << 1) + (x << 3) + (ch ^ 48),ch=getchar();
}

int a[N+1],n,ans=0;

int main()
{
	read(n);
	for (int i=1;i<=n;i++) read(a[i]);
	for (int i=1;i<=n;i++) ans+=max(0,a[i]-a[i-1]);
	printf("%d",ans);
	return 0;
}

评测结果