实验三
#include<math.h> #include<stdio.h> int main() { float a, b, c, x1, x2; float delta, real, imag; printf("Enter a,b,c: "); while(scanf("%f%f%f", &a, &b, &c) != EOF) { if (a == 0) printf("not quadratic equation.\n\n"); else { delta = b*b-4*a*c; if (delta >= 0) { x1 = (-b + sqrt(delta)) / (2 * a); x2 = (-b - sqrt(delta)) / (2 * a); printf("x1=%.2f,x2=%.2f\n\n", x1, x2); } else { real = -b / (2 * a); imag = sqrt(-delta) / (2 * a); printf("x1=%.2f+%.2fi,x2=%.2f-%.2fi\n\n", real, imag, real, imag); } } printf("Enter a,b,c:"); } return 0; }
任务2
#include<stdio.h> #include<stdlib.h> #include<time.h> #define N 5 int main() { int x, n; srand(time(0)); n = 0; do { n++; x = rand() % 10; printf("%3d", x); } while (n < N); printf("\n"); return 0; }
任务三
#include<math.h> #include<stdio.h> int main() { int n, c, m; c = 0; for (n = 101; n <= 200; n++) { for (m = 2; m <= sqrt(n); ++m) if (n % m == 0)break; if (m > sqrt(n)) { printf("%d\t", n); c++; if (c % 5 == 0) printf("\n"); } } printf("\n"); printf("100~200之间共有%d个素数", c); return 0; }
任务4
#include<stdio.h> int main() { int a, b, c, d; d = 1; c = 0; printf("输入一个数字:"); while (scanf("%d", &b) != EOF) { while (b >= 1) { a = b % 10; b = b / 10; if (a % 2 != 0) { c = c + a * d; d = d * 10; } } printf("新数字是%d\n", c); printf("输入一个数字:"); c = 0; d = 1; } return 0; }
任务5
#include<stdio.h> int main() { int a, b, c; float d, e; d = 0; e = 1; b = 1; c = 1; printf("Enter n(0~10):"); while (scanf("%d", &a) != EOF) { for (b = 1; b <= a; b++) { c = (-1) * c * b; d = d - e / c; } printf("n=%d,d=%f\n\n", c, d); } return 0; }
任务六
#include<stdio.h> #include<stdlib.h> #include<time.h> int main() { int a, b, c, d; srand(time(0)); a = (rand() % 31 + 1); printf("猜猜2020年12月哪一天是你的luck day\n\n"); printf("开始咯,你有三次机会,猜吧(1~31):"); scanf("%d", &a); printf("\n\n"); if (b == a) { printf("luck day"); } else if (b < a) { printf("你猜的日期早了,luck day还没到呢"); } else if (b > a) { printf("你猜的日期晚了,luck day悄悄溜到前面啦"); } printf("再猜(1~31:)"); scanf("%d", &c); printf("\n\n"); if (c == a) { printf("luck day"); } else if (c < a) { printf("你猜的日期早了,luck day还没到呢"); } else if (c > a) { printf("你猜的日期晚了,luck day悄悄溜到前面啦"); } printf("再猜(1~31:)"); scanf("%d", d); printf("\n\n"); if (d == a) { printf("luck day"); } else if (d < a) { printf("你猜的日期早了,luck day还没到呢"); printf("次数用完啦。偷偷告诉你:12月,你的luck day是%d号", a); } else if (d > a) { printf("你猜的日期晚了,luck day悄悄溜到前面啦"); printf("次数用完啦。偷偷告诉你:12月,你的luck day是%d号", a); } return 0; }