电话账单

https://www.acwing.com/problem/content/1495/

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <map>
#include <vector>

using namespace std;

const int N = 1010, M = 31 * 1440 + 10;

int n;
int cost[24];  // 每个时间段的话费
double sum[M];  // 从当月1号00:00开始到每个时刻所花费的钱数

struct Record
{
    int minutes;
    string state;
    string format_time;

    bool operator< (const Record& t) const
    {
        return minutes < t.minutes;
    }
};

map<string, vector<Record>> persons;

int main()
{
    for (int i = 0; i < 24; i ++ ) cin >> cost[i];
    for (int i = 1; i < M; i ++ ) sum[i] = sum[i - 1] + cost[(i - 1) % 1440 / 60] / 100.0;

    cin >> n;
    char name[25], state[10], format_time[20];
    int month, day, hour, minute;
    for (int i = 0; i < n; i ++ )
    {
        scanf("%s %d:%d:%d:%d %s", name, &month, &day, &hour, &minute, state);
        sprintf(format_time, "%02d:%02d:%02d", day, hour, minute);

        int minutes = (day - 1) * 1440 + hour * 60 + minute;
        persons[name].push_back({minutes, state, format_time});
    }

    for (auto &person : persons)
    {
        auto name = person.first;
        auto records = person.second;
        sort(records.begin(), records.end());

        double total = 0;
        for (int i = 0; i + 1 < records.size(); i ++ )
        {
            auto a = records[i], b = records[i + 1];
            if (a.state == "on-line" && b.state == "off-line")
            {
                if (!total) printf("%s %02d\n", name.c_str(), month);
                cout << a.format_time << ' ' << b.format_time;

                double c = sum[b.minutes] - sum[a.minutes];
                printf(" %d $%.2lf\n", b.minutes - a.minutes, c);
                total += c;
            }
        }

        if (total) printf("Total amount: $%.2lf\n", total);
    }

    return 0;
}