洛谷P4552

P4552 [Poetize6] IncDec Sequence

这题其实很有意思，当diff[2， n]都为0时，数组全等于a[1]

点击查看代码

#include<bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    int n; cin >> n;
    vector<ll>a(n + 1);
    vector<ll>diff(n + 2);
    for(int i = 1; i <= n; i++) {
        cin >> a[i];
        diff[i] = a[i] - a[i - 1];
    }

    ll sum_pos = 0, sum_neg = 0;
    for(int i = 2; i <= n; i++) {
        if(diff[i] > 0) sum_pos += diff[i];
        else sum_neg -= diff[i];
    }

    cout << max(abs(sum_pos), abs(sum_neg)) << '\n';
    cout << abs(sum_pos - sum_neg) + 1 << '\n';
    return 0;
}