代码

#include<cstdio>
using namespace std;
const int LEN=1<<19;
inline char gc(){
	static char buf[LEN+10],*PT=buf,*PTEND=buf+LEN;
	return ((PT==PTEND)&&(fread(buf,1,LEN,stdin),PT=buf)),*(PT++);
}
inline int getint(){
	int ans=0;
	char c=gc();
	while(c<'0'||c>'9')c=gc();
	while(c>='0'&&c<='9'){
		ans=ans*10+c-'0';
		c=gc();
	}
	return ans;
}
int main(){
    int n=getint();
    register char c;
    register int lst=0,x;
    int ans=0;
    for(register int i=n;i;--i){
	x=getint();
        x-lst>0&&(ans+=(x-lst));
        lst=x;
    }
    printf("%d",ans);
    return 0;
}

评测结果