BZOJ 3043: IncDec Sequence 差分 + 思维

Code:

#include <bits/stdc++.h>
#define setIO(s) freopen(s".in","r",stdin)
#define ll long long
#define maxn 100034
using namespace std;
ll a[maxn];
int main() {
   //  setIO("input");
    int n;
    scanf("%d",&n);
    for(int i=1;i<=n;++i) scanf("%lld",&a[i]);
    ll pos=0,neg=0;
    for(int i=n;i>1;--i) {
        if(a[i-1] > a[i]) pos+=a[i-1]-a[i];
        else neg+=a[i]-a[i-1];
    }
    printf("%lld\n%lld",max(pos, neg), abs(pos-neg)+1);
    return 0;
}