BC21 floating point numbers
describe
Given a floating point number, ask to get the single digit of the floating point number.
Enter description:
A line, including a float.
Output description:
A line containing an integer, the single digit corresponding to the input floating-point number.
Example 1
Input: 13.141
output: 1
important point:
For floating-point types, cast int will discard the fractional part.
#include <stdio.h>
int main(void)
{
int a;
scanf("%d",&a);
printf("%d",a%10);
return 0;
}BC22 How many seconds can you live
describe
Question: There are about 3.156×107s in a year, ask to enter your age, show how many seconds in that age.
Enter description:
A line, including an integer age (0<age<=200).
Output description:
A line containing an integer that prints the age in seconds.
Example 1
Input: 20
Output: 631200000
Note: The output data size must match the corresponding type, otherwise the result will be inaccurate. Such as float a = 0 and float a = 0.0 in the final result is different.
#include<stdio.h>
#include<math.h>
int main(void)
{
unsigned a;
scanf("%d", &a);
a = a * 3.156 * pow(10,7);
printf("%ld\n", a);
return 0;
}BC23 time conversion
describe
Given the number of seconds seconds (0 < seconds < 100,000,000), convert seconds to hours, minutes, and seconds.
Enter description:
A line containing an integer, the given number of seconds.
Output description:
A line containing three integers, followed by the hours, minutes, and seconds (possibly zero) corresponding to the input integers, separated by a space.
Example 1
Input: 3661
Output: 1 1 1
important point:
without
#include<stdio.h>
int main(void)
{
int a;
int b, c, d, e;
scanf("%d", &a);
b = a / 3600;
c = a % 3600;
d = c / 60;
e = c % 60;
printf("%d %d %d", b, d, e);
return 0;
}Average Calculation of BC24 Overall Score
describe
Input the grades of 3 subjects of a student in turn, and output the student's total grade and average grade on the screen.
Enter description:
One line, 3 subject scores, separated by a space.
Output description:
One line, total and average grades (with two decimal places), separated by a space.
Example 1
Input: 79.5 80.0 98.0
Output: 257.50 85.83
important point:
Pay attention to the type of data, if the floating point type is output with %d, the decimal part will be discarded. The sum can be represented by its English sum.
#include<stdio.h>
int main(void)
{
float a, b, c, d, e;
scanf("%f %f %f", &a, &b, &c);
d = a + b + c;
e = d / 3;
printf("%.2f %.2f", d, e);
return 0;
}BC25 Calculate Body Mass Index
describe
Problem: Calculate BMI (Body Mass Index). BMI (Body Mass Index, referred to as Body Mass Index, also known as Body Weight , English for Body Mass Index, referred to as BMI) is a number obtained by dividing the weight in kilograms by the square of the height in meters. A measure of thinness and health. Mainly used for statistical purposes, when we need to compare and analyze the health effects of a person's weight on people of different heights, the BMI value is a neutral and reliable indicator .
Enter description:
One line, two integers, representing weight (kg) and height (cm) respectively, separated by a space.
Output description:
One line, BMI index (with two decimal places).
Example 1
Input: 70 170
output: 24.22
important point:
Sometimes the questions are long, but the results are simple. Sometimes life is short, but the road is wonderful.
#include<stdio.h>
int main(void)
{
float a, b;
scanf("%f %f", &a, &b);
printf("%.2f", a / ((b / 100) * (b / 100)));
return 0;
}BC26 Calculate the perimeter and area of a triangle
describe
Calculate the perimeter and area of the triangle given its 3 sides a, b, c (0 < a, b, c < 100,000).
Enter description:
One line, three sides of a triangle (which can form a triangle), separated by a space.
Output description:
One line, the perimeter and area of the triangle (with two decimal places), separated by a space. For details of the output format, see the output example.
Example 1
Input: 3 3 3
输出：circumference=9.00 area=3.90
important point:
1. In this question, some people may not type the English word of perimeter incorrectly (o _ o);
2. Some people may not know that only the lengths of the three sides known to form a triangle are used to calculate the area. Here, the Qin Jiushao formula is used.
#include<stdio.h>
#include<math.h>
int main(void)
{
double a, b, c;
double d;
scanf("%lf %lf %lf", &a, &b, &c);
d = (a + b + c) / 2;
printf("circumference=%.2lf area=%.2lf", a + b + c, sqrt( d * (d - a) * (d - b) * (d - c)));
return 0;
}BC27 Calculate the volume of a sphere
describe
Given the radius of a sphere, calculate its volume. where the formula for the volume of a sphere is V = 4/3*πr3, where π = 3.1415926.
Enter description:
One line, the radius of the sphere as a float.
Output description:
One line, the volume of the sphere, with 3 decimal places.
Example 1
Input: 3.0
output: 113.097
important point:
Remember what BC22's attention points said? Now change 4.0 to 4 and 3.0 to 3 and try what the result will be.
#include<stdio.h>
#include<math.h>
int main(void)
{
double r;
scanf("%lf", &r);
printf("%.3lf", 4.0 / 3.0 * 3.1415926 * pow(r,3));
return 0;
}BC28 case conversion
describe
Convert uppercase and lowercase letters. Multiple sets of input and output.
Enter description:
Multiple sets of input, each line input capital letters.
Output description:
For each set of input and output the corresponding lowercase letter.
Example 1
Input: AB
output: ab
Remark:
In the multi-group input process, it should be noted that "carriage return" is also a letter, so the letter should be "absorbed" (getchar()).
important point:
1. See the title clearly: Multiple sets of input and output means that while(...);
2. Case conversion has its library function tolower in the c language, which is included in the header file ctype.h, but in order to be challenging, we still write a program ourselves without this function.
#include<stdio.h>
int main(void)
{
char ch;
while((ch = getchar()) != EOF)
{
if(ch >= 'A' && ch <= 'Z')
{
ch += 32;
}
putchar(ch);
}
return 0;
}BC29 Calculation of the nth power of 2
describe
On the basis of not using cumulative multiplication, the calculation of the nth power of 2 is realized by the shift operation (<<).
Enter description:
Multiple sets of input, each line input integer n (0 <= n < 31).
Output description:
For each set of inputs, output the corresponding result of the nth power of 2.
Example 1
Input: 2 10
Output: 4 1024
important point:
Calculated by shifting <<, for integers, shifting by one bit to the left is *2.
#include <stdio.h>
int main (void)
{
int n = 0;
while (scanf("%d",&n)!= EOF)
{
printf("%d\n", 1 << n);
}
return 0;
}BC30 KIKI and yogurt
describe
BoBo bought a box of yogurt, which contained n boxes of unopened yogurt. KiKi likes to drink yogurt, and found yogurt at the first time. KiKi can drink up one box of yogurt every h minutes, and KiKi won't drink another box of yogurt until m minutes have passed, how many unopened boxes of yogurt are left after m minutes?
Enter description:
Multiple sets of input, each set of input is only one line, including n, h and m (all integers). The input data guarantees that m <= n * h.
Output description:
For each set of input, the output is also only one line, and the number of unopened yogurt boxes remaining.
Example 1
Input: 8 5 16
output: 4
important point:
The difficulty of this question is still there, and those who can't think of it can write a few numbers to try it out. If you really can't, you can observe other people's code and internalize it into your own.
#include<stdio.h>
int main(void)
{
int n, h, m;
while(scanf("%d %d %d", &n, &h, &m) != EOF)
{
if(m % h != 0)
{
n = n - ((m / h) + 1);
}
else
{
n = n - (m / h);
}
printf("%d\n", n);
}
return 0;
}