IOS-C_DAY4___ Branching structure

2015.1.22

Single branch structure

if (conditional expression)

//{

Execute the statement;

//}

/*int Main (int argc, const char * argv[]) {

int score;

scanf ("%d", &score);

Error correction processing

if (score<0| | SCORE>100) {

return-1;

}

if (score >=90)

{

printf ("Excellent \ n");

return 0;

}

if (score>=70) {

printf ("Good \ n");

return 0;

}

if (score>=60) {

printf ("Pass \ n");

return 0;

}

printf ("Less than lattice \ n");

return 0;

}*/

Dual-branch structure

if (conditional expression)

//{

Execute statement 1;

//}

Else

//{

EXECUTE statement 2;

//}

The conditional expression establishes the Execution Statement 1, does not establish the execution statement 2;

int main (int argc,const char *argv[])

//{

int score;

scanf ("%d", &score);

if (score<0 | | score>100) {

printf ("Score input error \ n");

return-1;

//    }

//

if (score>=60) {

printf ("Pass \ n");

//    }

Else

//    {

printf ("Less than lattice \ n");

//    }

//

return 0;

//}

Determine whether the year is a leap or common year,

A leap year is one that can be divisible by 4 and not divisible by 100, or divisible by 400.

int main (int argc,const char *argv[])

//{

int year;

scanf ("%d", &year);

//

if ((!) ( year%4) && year%100) | | ! (year%400)) {

printf ("Leap year \ n");

//    }

Else

//    {

printf ("Common year \ n");

//    }

return 0;

//}

Multi-branch structure

if (expression 1)

//{

Statement list 1;

//}

else if (expression 2)

//{

Statement List 2;

//}

else if (expression 3)

//{

Statement list 3;

//}

//...

Else

//{

Statement list;

//}

/*int Main (int argc,const char *argv[])

{

int score;

scanf ("%d", &score);

if (score>=90 && score <=100) {

printf ("Excellent \ n");

}

else if (score >=70 && score <90)

{

printf ("Good \ n");

}

else if (score >=60 && score < 70)

{

printf ("Pass \ n");

}

else if (score >=0 && score < 60)

{

printf ("Less than lattice \ n");

}

Else

{

printf ("Input error \ n");

return-1;

}

return 0;

}

*/

1) Enter a month to determine which season the month belongs to

2 3 4 Spring

5 6 7 Summer

8 9 10 Fall

11 12 1 Winter

/* #include <stdlib.h>

int main (int argc, const char *argv[])

{

int month;

scanf ("%d", &month);

if (month<1| | MONTH>12) {

printf ("Month input error \ n");

return-1;

Exit (-1);

}

else if (month>=2 && month<=4)

{

printf ("Spring \ n");

}

else if (month>=5 && month<=7)

{

printf ("Summer \ n");

}

else if (month>=8 && month<=10)

{

printf ("Autumn \ n");

}

Else

{

printf ("Winter \ n");

}

return 0;

}*/

if (an expression)

//{

if (an expression)

//    {

//

//    }

Else

//    {

//

//    }

//}

Else

//{

if ()

//    {

//    }

else if ()

//    {

//

}else if ()

//    {

//

//    }

Else

//    {

//

//    }

//}

/*int Main (int argc,const char *argv[])

{

int choice, sex;

printf ("(1) Wine Heart Chocolate (2) Scallop chocolate (3) Nutty chocolate \ n");

printf ("Please enter your gender (1 boys, 2 girls):");

scanf ("%d", &sex);

printf ("Please enter your choice (1~~3):");

scanf ("%d", &choice);

if (sex<1 | | sex>2 | | choice <1 | | Choice >3) {

printf ("Input error \ n");

return-1;

}

if (sex==1) {//Boys

if (choice==1)

{

printf ("You are a master of love, very good for girls like \ \");

}

else if (choice ==2)

{

printf ("You are a timid person, always worried that you are not good enough \");

}

Else

{

printf ("You are all about girls, but she always does not feel");

}

}

else//Girls

{

if (choice==1) {

printf ("In love, you are often at a disadvantage \ n");

}

else if (choice==2)

{

printf ("You are a romantic person, in love can be a good adjustment atmosphere \ \");

}

Else

{

printf ("You are a strong woman, always ignore each other's feelings in love \ \");

}

}

return 0;

}

*/

If a university student's monthly consumption between 1-500 yuan for low consumption, between 501-1000 yuan for medium consumption, more than 1000 yuan for high consumption, 0 yuan for 0 consumption, 0 yuan below for negative consumption program to achieve

/* #include <math.h>

int main (int argc,const char *argv[])

{

float money;

scanf ("%f", &money);

if (Money >=0) {

if (!money) {

printf ("The student consumes \ 0");

}

else if (Money <=500)

{

printf ("The student low-spending%.2f rmb\n", money);

}

else if (Money <= 1000)

{

printf ("The student is medium-consumed%.2f rmb\n", money);

}

Else

{

printf ("The student consumes%.2f rmb\n", money);

}

}

Else

{

printf ("The student earns%.2f rmb\n", Fabs (Money)); The//fabs function evaluates the absolute value of the floating-point type data

}

return 0;

}*/

Switch statements

switch (expression)

//{

case constant Expression 1:

Statement list 1;

Break

Case constant Expression 2:

Statement List 2;

Break

Case constant Expression 3:

Statement list 3;

Break

//...

Default

Statement list;

Break

//}

int main (int argc,const char *argv[])

//{

int A, B;

Char ch;

scanf ("%d%c%d", &a, &ch, &b);//3+5 5*6 7-3

//

Switch (CH) {

Case ' + ':

printf ("a+b =%d\n", a+b);

Break;//break jump out of the switch switch statement

Case '-':

printf ("A-B =%d\n", A-a);

Break

Case ' * ':

printf ("a*b =%d\n", a*b);

Break

Case '/':

printf ("A/b =%d\n", A/b);

Break

default://Default Defaults

printf ("Input error \ n");

Break

//    }

//

return 0;

//}

Enter month judgment season

int main (int argc,const char *argv[])

{

int month;

scanf ("%d", &month);

Switch (month) {

Case 2:

Case 3:

Case 4:

printf ("Spring \ n");

Break

Case 5:

Case 6:

Case 7:

printf ("Summer \ n");

Break

Case 8:

Case 9:

Case 10:

printf ("Autumn \ n");

Break

Case 11:

Case 12:

Case 1:

printf ("Winter \ n");

Break

Default

printf ("Input error \ n");

Break

}

return 0;

}

Switch statement with break removed

int main (int argc,const char *argv[])

//{

int num;

scanf ("%d", &num);

//

Switch (num) {

Case 1:

printf ("Hello one\n");

Break

Case 2:

printf ("Hello two\n");

Break

Case 3:

printf ("Hello three\n");

Break

//

Default

Break

//    }

//

//

//}

IOS-C_DAY4___ Branching structure