100. 增减序列

题解

C++ 代码

#include <iostream>

using namespace std;

typedef long long LL;

const int N = 1e5 + 10;

int n;
int a[N];

int main()
{
    cin >> n;
    for(int i = 1; i <= n; i ++ ) scanf("%d", &a[i]);

    for(int i = n; i >= 2; i -- ) a[i] -= a[i - 1];

    LL pos = 0, neg = 0; // b2~bn的正数和，负数和的绝对值
    for(int i = 2; i <= n ;i ++ )
    {
        if(a[i] > 0) pos += a[i];
        else neg -= a[i];
    }

    cout << min(pos, neg) + abs(pos - neg) << endl;
    cout << abs(pos - neg) + 1 << endl;

    return 0;
}