#include <iostream>
using namespace std;
int main()
{int a, b, c;int sum = 0;for (int i = 100; i <= 999; ++i){a = i % 10;b = (i / 10) % 10;c = i / 100;sum = a * a * a + b * b * b + c * c * c;if (i == sum)cout << i<<" ";}
}
韓信點兵
/*沒能寫出直接輸入多行的情況，只能實現一行一行輸入*/
#include <iostream>
using namespace std;int main()
{//freopen("1.txt","r",stdin);int a, b, c;int flag = 0;int n = 0;while (scanf("%d %d %d", &a, &b, &c)==3){n++;for (int i = 10; i < 100; ++i){if (i % 3 == a && i % 5 == b && i % 7 == c){flag++;cout << "case " << n << ":" << i;break;}}if (flag == 0)cout << "No answer" << endl;cin.get();}return 0;
}
倒三角形
/*改進版打印沙漏*/
#include <iostream>
using namespace std;int main()
{int N;cin >> N;for (int i = N; i >= 1; --i){for (int j = N - i; j > 0; --j)cout << " ";for (int k = 1; k <= 2 * (i - 1) + 1; ++k)cout << "*";cout << endl;}for (int i = 2; i <= N; ++i){for (int j = N - i; j > 0; --j)cout << " ";for (int k = 1; k <= 2 * (i - 1) + 1; ++k)cout << "*";cout << endl;}
}
子序列的和
#include <iostream>
using namespace std;int main()
{//freopen("1.txt","r",stdin);long long n, m; //首先第一個注意的是平方溢出問題，所以要用longlongfloat sum = 0.0;int flag = 0;while (scanf("%lld %lld", &n, &m)==2 && n!=0 && m!=0){flag++;for (float i = n; i <= m; ++i) //其次，只有浮點數的計算才是浮點數，1是整數，所以i一定要是浮點數{sum += 1 / (i * i);}cout << "Case" << flag << ":";printf("%.5f\n", sum);sum = 0; //最后，sum一定要更新，否則會在原來的sum上進行累加出錯}
}
分數化小數
#include <iostream>
#include <iomanip>
using namespace std;int main()
{//freopen("1.txt","r",stdin);double a, b;double c;double res;while (scanf("%lf %lf %lf", &a, &b, &c) && a != 0, b != 0, c != 0){res = a / b;cout<< setiosflags(ios::fixed) << setprecision(c)<<res;//C++中格式化方式}
}
排列
#include <iostream>
using namespace std;int main()
{int a,b, c;for (a = 123; a < 329; ++a) //這里要限定一下最小的那個數字的范圍{b = 2 * a;c = 3 * a;int d[10]{};int flag = 0;d[a % 10]++;d[a / 10 % 10]++;d[a / 100]++;d[b % 10]++;d[b / 10 % 10]++;d[b / 100]++;d[c % 10]++;d[c / 10 % 10]++;d[c / 100]++;for (int i = 1; i <= 9; ++i){if (d[i] == 1)flag++;}if (flag == 9)cout << a << " " << b << " " << c<<endl;}
}
