实验2

#include<stdio.h>
int main() {
    int a = 5, b = 7, c = 100, d, e, f;

    d = a / b * c;
    e = a * c / b;
    f = c / b * a;
    printf("d=%d,e=%d,f=%d\n", d, e, f);

    return 0;
}

#include<stdio.h>
int main() {
    int x = 1234;
    float f = 123.456;
    double m = 123.456;
    char ch = ‘a‘;
    char a[] = "Hello,world!";
    int y = 3, z = 4;

    printf("%d %d\n", y, z);
    printf("y=%d,z=%d\n", y, z);
    printf("%8d,%2d\n", x, x);
    printf("%f,%8f,%8.1f,%0.2f,%.2e\n", f, f, f, f, f);
    printf("%1f\n", m);
    printf("%3c\n", ch);
    printf("%s\n%15s\n%10.5s\n%2.5s\n%.3s\n", a, a, a, a, a);

    return 0;
}

#include<stdio.h>
int main() {
    double x, y;
    char c1, c2, c3;
    int a1, a2, a3;

    scanf("%d%d%d", &a1, &a2, &a3);
    printf("%d,%d,%d\n", a1, a2, a3);
    scanf("%c%c%c", &c1, &c2, &c3);
    printf("%c%c%c\n", c1, c2, c3);
    scanf("%lf,%lf", &x, &y);
    printf("%lf,%lf\n", x, y);
    return 0;
}

#include<stdio.h>
int main() {
    char x;

    x = getchar();

    if ("x<=‘9‘&&x>‘0‘")
        printf("%c是数字字符\n", x);
    else if ("x<=‘z‘&&x>=‘a‘||x>=‘A‘&&x<‘Z‘")
    printf("%c是英文字母\n", x);
    else
    printf("%c是其他字符\n", x);

    return 0;
}

#include<stdio.h>
int main() {
    char ans1, ans2;

    printf("复习了没？(输入y或Y表示复习了，输入n或N表示没复习):");
    ans1 = getchar();

    getchar();

    printf("\n动手敲代码了没？(输入y或Y表示敲了，输入n或N表示木有敲):");
    ans2 = getchar();

    if ("ans1=y||ans1=Y")
        printf("\n罗马不是一天建成的:)\n");
    else
        printf("\n罗马不是一天毁灭的。。。\n");

    return 0;
}

#include<stdio.h>

#include<math.h>

int main() {

    int n, q, sum;

    q = 2;

    scanf("%d", &n);

    sum = 1 * (1 - pow(q, n)) / (1 - q);

    printf("n=%d时,sum=%d", n, sum);

    return 0;

}