全题最快代码! by SJZ08

#include <iostream>
#include <algorithm>
using namespace std;
int a[100005];
int main() {
	int n;
	scanf("%d",&n);
	for (int i=1;i<=n;i++) {
		scanf("%d",&a[i]);
	}
	long long sum=0;
	for (int i=1;i<=n;i++) {
		sum+=max(0,a[i]-a[i-1]);
	}
	printf("%lld",sum);
	return 0;
}