【新手上路】洛谷入门2：分支结构题单题解

代码如下：

#include<iostream>
#include<cstdio>
#include<cmath>
using namespace std;
int main() {int T;cin >> T;if (T == 1) {cout << "I love Luogu!";} else if (T == 2) {cout << 2 + 4 << " " << 10 - 2 - 4;} else if (T == 3) {cout<<3<<endl<<12<<endl<<2<<endl;} else if (T == 4) {printf("%.3lf\n",500.0/3.0);} else if (T == 5) {cout<<15<<endl;} else if (T == 6) {cout<<sqrt(6*6+9*9)<<endl;} else if (T == 7) {cout<<110<<endl<<90<<endl<<0<<endl;} else if (T == 8) {double const pi=3.141593;double const r=5;cout<<pi*r*2<<endl<<pi*r*r<<endl<<4.0/3*pi*r*r*r<<endl;} else if (T == 9) {cout<<22<<endl;} else if (T == 10) {cout<<9<<endl;} else if (T == 11) {cout<<100.0/(8-5)<<endl;} else if (T == 12) {cout<<13<<endl<<"R"<<endl;} else if (T == 13) {double const pi=3.141593;double V=pi*4*4*4*4/3+pi*10*10*10*4/3;cout<<floor(pow(V,1.0/3))<<endl;} else if (T == 14) {cout<<50<<endl;}return 0;
}

代码如下：

#include<iostream>
#include<math.h>
using namespace std;int main()
{int m,t,s;cin >> m >> t >> s;int left = m - ceil(float(s)/t);if(t == 0){cout << "0";}else{if(left < 0){cout << "0";}else{cout << left;}}}

代码如下：

#include<iostream>
using namespace std;int A(int x)
{int r = 0;if (x % 2 == 0){if (x > 4 && x <= 12){r = 1;}}return r;
}int U(int x)
{int r = 0;if (x % 2 == 0){r = 1;}if (x > 4 && x <= 12){r = 1;}return r;
}int B(int x)
{int r = 0;if (x % 2 == 0){r = 1;if (x > 4 && x <= 12){r = 0;}}if (x > 4 && x <= 12){r = 1;if (x % 2 == 0){r = 0;}}return r;
}int Z(int x)
{int r = 1;if (x % 2 == 0){r = 0;}if (x > 4 && x <= 12){r = 0;}return r;
}int main()
{int x;cin >> x;cout << A(x) << " " << U(x) << " " << B(x) << " " << Z(x);}

代码如下：

#include<iostream>
using namespace std;int is_leap_year(int n)
{int r = 0;if (n % 4 == 0){r = 1;if (n % 100 == 0 && n % 400 != 0){r = 0;}}return r;
}int main()
{int n;cin >> n;cout << is_leap_year(n);}

代码如下：

#include<iostream>
using namespace std;int main()
{int x;cin >> x;if(x <= 1){cout << "Today, I ate " << x << " apple.";}else{cout << "Today, I ate " << x << " apples.";}
}

代码如下：

#include<iostream>
using namespace std;string compare(int n)
{string r;if (5 * n < 3 * n + 11){r = "Local";}else{r = "Luogu";}return r;
}int main()
{int n;cin >> n;cout << compare(n);
}

代码如下：

#include<iostream>
using namespace std;int main()
{float m,h;cin >> m >> h;float BMI = m/(h*h);if(BMI < 18.5){cout << "Underweight";}if(BMI >= 18.5 && BMI < 24){cout << "Normal";}if(BMI >= 24){cout << BMI << endl << "Overweight";}
}

代码如下：

#include<iostream>
using namespace std;int main()
{int a,b,c,temp;cin >> a >> b >> c;if(a >= b){temp = a;a = b;b = temp;}if(a >= c){temp = a;a = c;c = temp;}if(b >= c){temp = b;b = c;c = temp;}cout << a << " " << b << " " << c;
}

代码如下：

#include<iostream>
using namespace std;int is_leap_year(int y)
{int r = 0;if(y % 4 == 0){r = 1;if(y % 100 == 0 && y % 400 != 0){r = 0;}}return r; 
}int main()
{int y,m;cin >> y >> m;if(m == 1 || m == 3 || m == 5 || m == 7 || m == 8 || m == 10 || m == 12){cout << "31";}if(m == 4 || m == 6 || m == 9 || m == 11){cout << "30";}if(m == 2){if(is_leap_year(y) == 1){cout << "29";}if(is_leap_year(y) == 0){cout << "28";}}}

代码如下：

#include<bits/stdc++.h>
using namespace std;
int main(){int hour[7],maxx = 0,ans=0;for(int i=0;i<7;++i) {int a,b;cin >> a >> b;hour[i] = a+b;maxx = max(a+b,maxx);}for(int i=0;i<7;++i) {if((hour[i] > 8) && (hour[i] == maxx)) {ans = i+1;break;}}cout << ans;
}

代码如下：

#include<bits/stdc++.h>
using namespace std;
int main(){int index = 1000000000;float n;cin >> n;for(int i=0;i<n;++i){float q;int pri;cin >> q >> pri;index = min(index,int(ceil(n/q)*pri));}cout << index << endl;
}

代码如下：

#include <bits/stdc++.h>
using namespace std;
int main()
{int l[3];cin >> l[0] >> l[1] >> l[2];// 调整长度sort(l, l + 3, greater<int>()); // 大到小if (l[1] + l[2] <= l[0]){cout << "Not triangle" << endl;}else {if (l[1] * l[1] + l[2] * l[2] == l[0] * l[0]) cout << "Right triangle" << endl;if (l[1] * l[1] + l[2] * l[2] > l[0] * l[0]) cout << "Acute triangle" << endl;if (l[1] * l[1] + l[2] * l[2] < l[0] * l[0]) cout << "Obtuse triangle" << endl;if (l[1] == l[2] || l[0] == l[1]) cout << "Isosceles triangle" << endl;if (l[0] == l[2]) cout << "Equilateral triangle" << endl;}
}

代码如下：

#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{int n;cin >> n;if (n <= 150){printf("%.1f", 0.4463 * n);}else if (n <= 400){printf("%.1f", 0.4463 * 150 + (n - 150) * 0.4663);}else{printf("%.1f", 0.4463 * 150 + 0.4663 * 250 + (n - 400) * 0.5663);}
}

代码如下：

#include <bits/stdc++.h>
using namespace std;
int main()
{int x, n;cin >> x >> n;if (x > 5){n -= (7 - x + 1);int n_week_time = n / 7 * 1250;int left;if (n % 7 > 5){left = 1250;}else{left = n % 7 * 250;}cout << n_week_time + left;}else{n = n - (7 - x + 1);int first_week = (5 - x + 1) * 250;int n_week_time = n / 7 * 1250;int left;if (n % 7 > 5){left = 1250;}else{left = n % 7 * 250;}cout << first_week + n_week_time + left;}
}

代码如下：

#include <bits/stdc++.h>
using namespace std;int gcd(int big, int small)
{return 0 == small ? big : gcd(small, big % small);
}
int main()
{int a[3];cin >> a[0] >> a[1] >> a[2];sort(a, a + 3);// 最小锐角正弦值应该是最小边比上最大边cout << a[0] / gcd(a[2], a[0]) << "/" << a[2] / gcd(a[2], a[0]);
}

代码如下：

#include<bits/stdc++.h>
using namespace std;
int main(){int apple[11]={0};for(int i=0;i<11;++i) {cin >> apple[i];}int cnt=0,high = apple[10]+30;for(int i=0;i<10;++i) {if(apple[i] <= high) ++cnt;}cout << cnt;
}

代码如下：

#include <bits/stdc++.h>
using namespace std;
int main()
{int num[3];cin >> num[0] >> num[1] >> num[2];sort(num, num + 3);string s;cin >> s;cout << num[int(s[0] - 65)] << " " << num[int(s[1] - 65)]<< " " << num[int(s[2] - 65)];
}

代码如下：

#include<iostream>
#include<stdio.h>
using namespace std;
int main(){int a1,a2,a3,a4,a5,a6,a7,a8,a9;char a0;scanf("%1d-%1d%1d%1d-%1d%1d%1d%1d%1d-%c",&a1, &a2, &a3, &a4, &a5, &a6, &a7, &a8, &a9, &a0);int a = (a1+a2*2+a3*3+a4*4+a5*5+a6*6+a7*7+a8*8+a9*9)%11;if(int(a0-'0')==a || (a==10 && a0 == 'X')) cout << "Right";else if(a==10) printf("%d-%d%d%d-%d%d%d%d%d-X",a1,a2,a3,a4,a5,a6,a7,a8,a9);else printf("%d-%d%d%d-%d%d%d%d%d-%d",a1,a2,a3,a4,a5,a6,a7,a8,a9,a);
}