C 语言知识点自查表

变量

• int, long long, short, unsigned int
• float, double, long double
• char

运算

• +, -, *, /, %
• +=, -=, *=, /=, %=
• ++, --
• 强制转换规则
• &, |, ^, !, ~, <<, >>
• &&, ||
• sqrt(x), fabs(x), log(x), log10(x), exp(x), pow(x, y), sin(x) in math.h.
• 浮点数比较

交互

输入输出

• printf("%d", x)

• %d, %f, %u, %e, %c

• %md, %.nf

• %%, \n, \t

• scanf("%lf", &x)

• scanf("%c,%c")

• while (scanf("%d%d", &n, &m) != EOF)

• scanf("%2d%*2d%2d", &a, &b)

• ch = getchar()

• putchar(ch)

• puts("abc")

文件操作

• program.exe < data.in > data.out

•   FILE *fopen(const char *filename, const char *mode);
    int fclose(FILE *fp);
    int fputc(int ch, FILE *fp);
    int fgetc(FILE *fp);
    int fputs(const char *str, FILE *fp);
    char *fgets(char *str, int n, FILE *fp);
    int fprintf(FILE *fp, const char *format, ...);
    int fscanf(FILE *fp, const char *format, ...);
    size_t fwrite(const void *ptr, size_t size, size_t count, FILE *fp);
    size_t fread(void *ptr, size_t size, size_t count, FILE *fp);
    FILE *freopen(const char *filename, const char *mode, FILE *stream);
  

• r(b)/w(b)/a(b)(+)

流程控制

分支

• if (...) { ... } else { ... }

•   switch (x) {
        case 'x1':
            ...
            break;
        case 'x2':
            ...
            break;
        default:
            ...
            break;
    }
  

循环

• for (int i = 0; i < n; i++)
• while (x) { ... }
• rand() and time.h
• continue, break
• do { ... } while (x)
• goto

高级数据类型

数组

• int a[10]
• int x[10] = {0}
• int a[10][10]
• int a[3][3] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}
• 数组传参
• memset(a, 0, sizeof a)
• 字符串输入
• 字符串输出
• strlen(s)

指针

• int *x
• &x
• *x
• swap(x, y)
• NULL
• int (*f) (int a, int b)
• 指针是可以加整数的

结构体

• struct node { int id; char name[10]; };
• typedef long long int
• node x = {1, "CCA"}
• 结构体嵌套
• 结构体指针

函数

• int(void) func(int x, char *y) { return (x); }
• assert
• 分而治之
• 变量的作用域
• 模块化