1.(逻辑运算符优先级：非>与>或) (1)!a||a：1(TRUE) (2)a&&!a：0(FALSE) (3)!a||(a&&1)：1(TRUE) (4)a&&(!a||1)：1(TRUE)
2.语句如下： (1)x<z ^ y<z (2)x<0&&y<0&&z>=0 || x<0&&y>=0&&z<0 || z>=0&&y<0&&z<0 (3)!(x&1)
3.代码如下：
#include <stdio.h> int main() { int n; printf("请输入后推天数N："); scanf("%d", &n); char* str; switch ((n+5)%7) { case 0: str = "星期一"; break; case 1: str = "星期二"; break; case 2: str = "星期三"; break; case 3: str = "星期四"; break; case 4: str = "星期五"; break; case 5: str = "星期六"; break; default: str = "星期日"; break; } printf("%s", str); return 0; }4.代码如下(暴力求解)：
#include <stdio.h> #include <stdlib.h> // 从大到小 int cmpFunc (const void *a, const void *b) { return -(*(int*)a - *(int*)b); } int main() { int values[4]; for (int i = 0; i < 4; i++) { scanf("%d", &values[i]); } qsort(values, 4, sizeof(int), cmpFunc); for (int i = 0; i < 4; i++) { printf("%d ", values[i]); } printf("\n"); return 0; }5.代码如下：
#include <stdio.h> #include <math.h> int main() { double x, result; printf("请输入函数自变量x："); scanf("%lf", &x); if (x <= 0) { result = 0; } else if (x <= 10) { result = x; } else { result = 0.5 + sin(x); } printf("%.2f", result); return 0; }6.代码如下：
#include <stdio.h> #include <ctype.h> int main() { char c; char *result; printf("请输入一个字符："); scanf("%c", &c); if (isupper(c)) { result = "大写字母"; } else if (islower(c)) { result = "小写字母"; } else if (isdigit(c)){ result = "数字"; } else { result = "其他"; } printf("%c是%s字符", c, result); return 0; }7.代码如下：
#include <stdio.h> #include <ctype.h> int main() { double profit = 0, reward = 0; printf("请输入当月利润："); scanf("%lf", &profit); if (profit < 50000) { reward = 0; } else if (profit < 100000) { reward = 0.1 * profit; } else if (profit < 200000){ reward = 0.075 * profit; } else if (profit < 300000){ reward = 0.05 * profit; } else { reward = 0.02 * profit; } printf("奖金总额是：%.2lf元", reward); return 0; }8.代码如下：
#include <stdio.h> int main() { int num, a, b; printf("请输入一个不大于三位数的正整数："); scanf("%d", &num); a = num / 100; num %= 100; b = num / 10; num %= 10; printf("%d", a+b+num); return 0; }9.代码如下：
#include <stdio.h> int main() { int num, a, b; printf("请输入一个两位的正整数："); scanf("%d", &num); if (num < 10 || num > 99) { printf("输入数据不合法"); return -1; } a = num / 10; b = num % 10; printf("%d", (a > b ? a+b*10 : num)); return 0; }10.代码如下：
#include <stdio.h> int main() { // Monday Tuesday Wednesday Thursday Friday Saturday Sunday char tempChar; char *day; printf("请输入代表星期几的字符："); tempChar = getchar(); switch (tempChar) { case 'm': case 'M': day = "星期一"; break; case 'w': case 'W': day = "星期三"; break; case 'f': case 'F': day = "星期五"; break; case 't': case 'T': tempChar = getchar(); if (tempChar == 'u') { day = "星期二"; } else if (tempChar == 'h') { day = "星期四"; } else { printf("输入错误！"); return -1; } break; case 's': case 'S': tempChar = getchar(); if (tempChar == 'a') { day = "星期六"; } else if (tempChar == 'u') { day = "星期日"; } else { printf("输入错误！"); return -1; } break; default: printf("输入错误！"); return -1; } printf("你输入的是%s", day); return 0; }Chapter05 迭代计算与循环结构
返回索引页
