金字招牌

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#include<iostream>
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int Fack(int n)
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{
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  int i,sum=1;
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  for(i=1;i<=n;i++)
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  {
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    sum*=i;
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  }
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  return sum;
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}
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int main()
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{
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  int n;
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  std::cin>>n;
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  std::cout<<Fack(n)<<std::endl;
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  return 0;
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}

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#include <iostream>
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void zuheshu(int m, int k, long long &ret)
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int main() {
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  int m, k;
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  long long ret;
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  std::cin >> m >> k;
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  zuheshu(m, k, ret);
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  std::cout << ret << std::endl;
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  return 0;
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}
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#include<iostream>
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void zuheshu(int m, int k, long long &ret) // C++引用
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{
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  if (k < 0 || k > m) {
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    ret = 0;
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    return;
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  }
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  if (k > m - k) k = m - k;
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  long long result = 1;
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  for (int i = 1; i <= k; ++i) {
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    result = result * (m - k + i) / i; //通过组合数公式求解，避免算阶乘溢出
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  }
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  ret = result;
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}

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#include<stdio.h>
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#include<math.h>
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double dist(double x1, double y1, double x2, double y2);
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int main(void)
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{
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  double x1, y1, x2, y2;
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  printf("Enter x1,y1,x2, y2:");
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  scanf("%lf %lf %lf %lf", &x1, &y1,&x2,&y2);
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  printf("dist=%.2f\n", dist(x1,y1,x2,y2));
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  return 0;
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}
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double dist(double x1, double y1, double x2, double y2)
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{
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  return sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
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}

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#include<iostream>
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void pyramid (int n);
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int main()
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{
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  int n;
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  std::cin>>n;
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  pyramid(n);
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  return 0;
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}
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void pyramid(int n) {
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  for (int i = 1; i <= n; ++i) {       // 输出前导空格，使金字塔居中
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    for(int j = 0;j<n-i;j++)
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      std::cout<<" ";              // 输出 i 重复 i 次，中间用空格分隔
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    for (int k = 1; k <= i; ++k) {
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      std::cout << i;
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      if (k < i)
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        std::cout << " ";        // 数字之间加空格
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    }
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    std::cout << std::endl;
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  }
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}

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#include<iostream>
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void daily(double &study, double &relax) { //计算每天努力和每天放任
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  study = pow(1.01,365);   // 每天努力 1%
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  relax = pow(0.99,365);   // 每天放任 1%
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}
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void weekdays(double &result) {  //计算工作日努力，周末放任
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  double val = 1.0;
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  for (int day = 0; day < 365; ++day) {
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    if (day % 7 < 5)   // 工作日努力
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      val *= 1.01;
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    else               // 周末放任
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      val *= 0.99;
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  }
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  result = val;
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}
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double find_required_rate() {
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/* 每周工作5天，休息2天，休息日水平下降1%，工作日要努力到什么程度，
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  一年后的水平才与每天努力1%取得的效果一样呢？
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*/
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  double target = pow(1.01, 365);
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  double low = 0.0, high = 0.1;
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  for (int i = 0; i < 100; ++i) {
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    double mid = (low + high) / 2;  // 二分法查找
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    double val = 1.0;
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    for (int day = 0; day < 365; ++day) {
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      if (day % 7 < 5)   // 工作日
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        val *= (1.0 + mid);
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      else               // 休息日
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        val *= 0.99;
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    }
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    if (val < target)
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      low = mid;
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    else
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      high = mid;
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  }
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  return (low + high) / 2;
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}
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int main()
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{
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  double dailystudy,dailyrelax,weekdaystudy,result;
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  daily(dailystudy,dailyrelax);
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  weekdays(weekdaystudy);
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  result = find_required_rate();
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  //std::cout << std::fixed << std::setprecision(2); // 调用#include <iomanip>取两位小数
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  std::cout << "365天，每天学习" << dailystudy << std::endl;
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  std::cout << "365天，每天放任" << dailyrelax << std::endl;
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  std::cout << "365天，工作日学习，周末放任" << weekdaystudy << std::endl;
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  std::cout << "每周工作5天，休息2天，休息日水平下降1%，工作日要努力到"
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  << result*100 << "%，一年后的水平才与每天努力1%取得的效果一样" << std::endl;
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  return 0;
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}