C++ PAT训练7

[算法组-唐梓涵]

1026

#include <iostream>
#include<cmath>
using namespace std;
int main() {
	int num1, num2,h,m,s;
	cin >> num1 >> num2;
	int diff = num2 - num1;
	int data = round(diff / 100.0);
	h = data / 3600;
	m = data % 3600 / 60;
	s = data % 3600 % 60;
	printf("%02d:%02d:%02d", h, m,s);
}

1027

求数列前n项和

#include<iostream>
#include<cmath>
using namespace std;
int main() {
	int num;
	char sym;
	cin >> num >> sym;
	int n = 0;
	while (num > 2 * pow(n+1, 2) + 1) {//手动计算
		n++;
	}
	int count = n;
	for (int i = 0; i < 2 * n +1; i++) {
		string output(2*abs(count)+1, sym);
		string space(n-abs(count), ' ');
		output = space + output;
		cout << output<<endl;
		count--;
	}
	cout << num- 2 * pow(n + 1, 2) + 1<<endl;
}

1028

字符串比较更快捷

#include<iostream>
#include<string>
using namespace std;
int main() {
	int N;
	cin >> N;
	string max[2], min[2];
	max[1] = "0000/00/00";
	min[1] = "9999/99/99";
	int count=0;
	for (int i = 0; i < N; i++) {
		string name, birth;
		cin >> name >> birth;
		if ("2014/09/06" >= birth && birth >= "1814/09/06") {
			if (birth > max[1]) {
				max[0] = name;
				max[1] = birth;
			}
			if (birth < min[1]) {
				min[0] = name;
				min[1] = birth;
			}
			count++;
		}
	}
		cout << count << " " << min[0] << " " << max[0];
}

1029

字符串相减

#include<iostream>
#include<string>
using namespace std;

int main() {
    string a;
    string b;
    getline(cin, a);
    getline(cin, b);
    for (int i = 0; i < b.size(); i++) {
        for (size_t j = 0; j < a.size();) { 
            if (a[j] == b[i]) {
                a.erase(j, 1); 
            }
            else {
                j++; 
            }
        }
    }
    string result;
    for (size_t i = 0; i < a.size(); i++) { 
        a[i] = toupper(a[i]); 
        if (result.find(a[i]) == string::npos) { 
            result.push_back(a[i]);
        }
    }
    cout << result;
}