Informatics Olympiad 1.2: Sequence structure programming (2)

​The first part of C++ language

Chapter 2 Sequence Structure Program Design

Section 4 Data Input and Output

1024 floating point number with 3 decimal places

#include <cstdio>
using namespace std;

int main() {
    float a;

    scanf("%f", &a);
    printf("%.3f\n", a);
​
    return 0;
}

1025 Floating point number with 12 decimal places

#include <cstdio>
using namespace std;

int main() {
    double a;

    scanf("%lf", &a);
    printf("%.12lf\n", a);

    return 0;
}

1026 Space separated output

#include <cstdio>
using namespace std;

int main() {
    char a;
    int b;
    float c;
    double d;

    scanf("%c %d %f %lf", &a, &b, &c, &d);
    printf("%c %d %f %lf\n", a, b, c, d);

    return 0;
}

1027 Output floating point number

#include <cstdio>
using namespace std;

int main() {
    double a;

    scanf("%lf", &a);
    printf("%f\n%.5f\n%e\n%g\n", a, a, a, a);

    return 0;
}

1028 character diamond

#include <cstdio>
using namespace std;

int main() {
    char c;

    scanf("%c", &c);
    printf("  %c\n", c);
    printf(" %c%c%c\n", c, c, c);
    printf("%c%c%c%c%c\n", c, c, c, c, c);
    printf(" %c%c%c\n", c, c, c);
    printf("  %c\n", c);

    return 0;
}

Section 5 Example of Sequence Structure

1029 Calculate the remainder of the division of floating-point numbers

#include <iostream>
using namespace std;

int main() {
    double a, b, r;

    cin >> a >> b;
    r = a - int(a / b) * b;
    cout << r << endl;

    return 0;
}

1030 Calculate the volume of the ball

#include <cstdio>
using namespace std;

int main() {
    double r, V;

    scanf("%lf", &r);
    V = 4.0 / 3.0 * 3.14 * r * r * r;
    printf("%.2lf\n", V);

    return 0;
}

1031 Reverse output a three-digit number

#include <cstdio>
using namespace std;

int main() {
    int a;

    scanf("%d", &a);
    printf("%d%d%d\n", a%10, a/10%10, a/10/10);

    return 0;
}

1032 Elephant Drinking Water

#include <cstdio>
#include <cmath>
using namespace std;

int main() {
    int h, r, x;

    scanf("%d %d", &h, &r);
    x = ceil(20000 / (3.14 * r * r * h));
    printf("%d\n", x);
    return 0;
}

1033 Calculate the length of the line segment

#include <cstdio>
#include <cmath>
using namespace std;

int main() {
    double xa, ya, xb, yb, len;

    scanf("%lf %lf %lf %lf", &xa, &ya, &xb, &yb);
    len = sqrt((xb - xa) * (xb - xa) + (yb - ya) * (yb - ya));
    printf("%.3lf\n", len);

    return 0;
}

1034 Calculate the area of ​​a triangle

#include <cstdio>
#include <cmath>
using namespace std;

int main() {
    float x1, y1, x2, y2, x3, y3;
    double a, b, c, p, s;

    scanf("%f %f %f %f %f %f", &x1, &y1, &x2, &y2, &x3, &y3);
    a = sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1));
    b = sqrt((x3 - x2) * (x3 - x2) + (y3 - y2) * (y3 - y2));
    c = sqrt((x1 - x3) * (x1 - x3) + (y1 - y3) * (y1 - y3));
    p = (a + b + c) / 2;
    s = sqrt(p * (p - a) * (p - b) * (p - c));

    printf("%.2lf\n", s);

    return 0;
}

1035 Calculation of the last term of the arithmetic sequence

#include <cstdio>
using namespace std;

int main() {
    int a1, a2, n;

    scanf("%d %d %d", &a1, &a2, &n);
    printf("%d\n", a1 + (a2 - a1) * (n - 1));

    return 0;
}

1036 AxB problem

#include <cstdio>
using namespace std;

int main() {
    int A, B;

    scanf("%d %d", &A, &B);
    printf("%lld\n", (long long)A * (long long)B);

    return 0;
}

1037 Calculate the power of 2

#include <cstdio>
#include <cmath>
using namespace std;

int main() {
    int n;

    scanf("%d", &n);
    printf("%d\n", (int)pow(2, n));

    return 0;
}

1038 Apple and Bug

#include <cstdio>
#include <cmath>
#include <algorithm>

using namespace std;

int main() {
    int n, x, y, left, ans;

    scanf("%d %d %d", &n, &x, &y);
    left = n - ceil(1.0 * y / x);
    printf("%d\n", max(0, left));

    return 0;
}

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