解题报告 『[Poetize6]IncDec Sequence（差分）』

原题地址

差分,想到了这个再看看代码应该就很好做了。

 

代码实现如下：

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define rep(i, a, b) for (register int i = (a); i <= (b); i++)
#define per(i, a, b) for (register int i = (a); i >= (b); i--)

const int maxn = 1e5 + 5;

int n, pos = 0, neg = 0;
int a[maxn]; 

int MAX(int a, int b) {return a > b ? a : b;}

int ABS(int a, int b) {return a > b ? a - b : b - a;}

int read() {
    int x = 0, flag = 0;
    char ch = ' ';
    while (ch != '-' && (ch < '0' || ch > '9')) ch = getchar();
    if (ch == '-') {
        flag = 1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9') {
        x = (x << 1) + (x << 3) + (ch ^ '0');
        ch = getchar();
    }
    return flag ? -x : x;
}

void write(int x) {
    if (x < 0) {
        putchar('-');
        x = -x;
    }
    if (x > 9) write(x / 10);
    putchar(x % 10 + '0');
}

signed main() {
    n = read();
    rep(i, 1, n) a[i] = read();
    per(i, n, 2) a[i] -= a[i - 1];
    rep(i, 2, n) {
        if (a[i] > 0) pos += a[i];
        if (a[i] < 0) neg -= a[i];
    }
    write(MAX(pos, neg));
    printf("\n");
    write(ABS(pos, neg) + 1);
    return 0;
}