CodeForces - 10A Power Consumption Calculation【水题】

【题目描述】
Tom is interested in Power consumption of his favourite laptop. His laptop has three modes. In normal mode laptop consumes P1 watt per minute. T1 minutes after Tom moved the mouse or touched the keyboard for the last time, a screensaver starts and power consumption changes to P2 watt per minute. Finally, after T2 minutes from the start of the screensaver, laptop switches to the “sleep” mode and consumes P3 watt per minute. If Tom moves the mouse or touches the keyboard when the laptop is in the second or in the third mode, it switches to the first (normal) mode. Tom’s work with the laptop can be divided into n time periods [l1, r1], [l2, r2], …, [ln, rn]. During each interval Tom continuously moves the mouse and presses buttons on the keyboard. Between the periods Tom stays away from the laptop. Find out the total amount of power consumed by the laptop during the period [l1, rn].

【输入】
The first line contains 6 integer numbers n, P1, P2, P3, T1, T2 (1 ≤ n ≤ 100, 0 ≤ P1, P2, P3 ≤ 100, 1 ≤ T1, T2 ≤ 60). The following n lines contain description of Tom’s work. Each i-th of these lines contains two space-separated integers li and ri (0 ≤ li < ri ≤ 1440, ri < li + 1 for i < n), which stand for the start and the end of the i-th period of work.

【输出】
Output the answer to the problem.

【样例输入1】
1 3 2 1 5 10
0 10

【样例输出1】
30

【样例输入2】
2 8 4 2 5 10
20 30
50 100

【样例输出2】
570

题目链接：https://codeforces/contest/10/problem/A

某人的电脑在使用时功耗为P1，不使用经过T1时间后功耗变为P2，在经过T2时间后功耗变为P3，求从L1（唯一坑点，不是0开始）到Rn的时间内电脑的功耗。

代码如下：

#include <iostream>
using namespace std;
static const int MAXN=1e2+10;
int l[MAXN],r[MAXN];
int n,P1,P2,P3,T1,T2;
int res=0;
int main()
{
    cin>>n>>P1>>P2>>P3>>T1>>T2;
    for(int i=1;i<=n;i++)
    {
        cin>>l[i]>>r[i];
        res+=P1*(r[i]-l[i]);
        if(i==1) continue;
        int t=l[i]-r[i-1];
        res+=P1*min(T1,t)+P2*min(T2,max(t-T1,0))+P3*max(t-T1-T2,0);
    }
    cout<<res<<endl;
    return 0;
}