代码

#include<bits/stdc++.h>
using namespace std;
inline int getint(){
    int ans=0;
    char c=getchar();
    while(c<'0'||c>'9')c=getchar();//' '<'0'
    while(c>='0'&&c<='9'){
    	ans*=10;
        ans+=c-'0';
        c=getchar();
    }
    return ans;
}

int main(){
    int n=getint();
    register int lst=0,ans=0,x;
    for(register int i=n-1;i;--i){
        x=getint();
        if(x-lst>0)ans+=x-lst;
        lst=x;
    }
    printf("%d",ans);
    return 0;
}

评测结果