《C语言课程设计案例精编》课件 3

1、Source file_1Source file_iSource file_n.Function_1Function_nFunction_1.C program.exeCompileStatementsDeclaration StatementsExecutive StatementsControl-flow StatementsExpression StatementsNull StatementsCompound StatementsSelection StatementsIteration StatementsJump StatementsComment StatementsLabele

2、d StatementsComment statementDeclaration statementCompound statementSelection statementExpression statementNull statementIdentifier: switchSelection StatementsIf statementIf-else statementswitch statementconditionstatementTrueFalseconditionStatement_1TrueFalseStatement_2#include main( ) int a, b, ma

3、x; printf (Input a and b=); scanf (%d %d, &a, &b); max=a; /* assume a is bigger one */ if ( max b ) max=b; /* b is bigger*/ printf(The max of a and b : %dn, max);max bmax= bTrueFalse#include main( ) int a, b, max; printf (Input a and b=); scanf (%d %d, &a, &b); if ( ab ) max=a; /* ab

4、, a-max */ else max=b; /* amax */ printf (The max of a and b : %dn, max);ab?max=aTruemax=bFalseNotice:Sometimes, If-else statement and condition expression could convert each other! max=(ab) ? a : b ; Condition expressionassignment statementIf-else statementb?a/bTruecannotFalseif (b) printf (“%dn”,

5、a/b);else printf (“error.n”);EquivalentHow to match multiple if and else? A else match with the previous, closest, and no-matching if. if ( x != y ) if ( x y ) printf (XYn); else printf (X=abWhen a=90) printf(An);else if (a=80) printf(Bn);else if (a=70) printf(Cn);else if (a=60) printf(Dn);else prin

6、tf(En);if (a=90) printf(An);if (a=80) printf(Bn);if (a=70) printf(Cn);if (a=60) printf(Dn);if (a=90) printf(An);else if (a=80) printf(Bn); else if (a=70) printf(Cn); else if (a=60) printf(Dn); else printf(En); Stat 1Nexpr 1Yexpr 2expr mYYStat 2Stat mStat nNNelse ifScoresDivide scores into five level

7、s：90,80-89, 70-79, 60-69, =0 & =100) switch (int)(fs/10) case 10: case 9: printf(“An”); break; case 8: printf(“Bn”); break; case 7: printf(“Cn”); break; case 6: printf(“Dn”); break; default: printf(“En”); 将将分分数数分分为为五五个个分分数数段段conditionstatementTrueFalseconditionStatement_1TrueFalseStatement_2Expr

8、ession_1Statement_1Expression_2Statement_2.Expression_nStatement_n Stat 1Nexpr 1Yexpr 2expr mYYStat 2Stat mStat nNNelse if* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *PAAYYNNwhileuntilPwhiledo-whileforIteration StatementswhileuntilexprStatementYNLoop b

9、odyindex =1;While ( - index5) printf (“ Good morning!n”);Dead loop(cannot stop)Dead loop(cannot stop)Conclusion The loop condition should make loop stop normally!Null statementint i=1; while (i = 100) sum += i+;int i=0;while (+i = 100) sum += i;int i=0;while (i + 100) sum += i;int i=0;while (i 100)

10、sum += +i;Iteration Algorithm=100; sum+=; i+i; =100; sum+=;100; i+; sum+=; 100; +i; sum+=;When i=6, j=5Value=301= i = 91= j = istatementExpr?Statement after do-whileNYloop conditionLoop bodyQuestion: how to convert this program by using while structure? What are their differences?Usual form:for (ini

11、tialization; condition; + + or - -)Expr1;Expr2?Expr3;statementNYStatement after forinitializationloop conditionLoop bodyOutput: 1!= 1 2!= 2 3!= 6 4!= 24 5!= 120 6!= 720 7!= 5040 8!= 40320 9!= 362880 10!= 3628800Nested loop structure!嵌套循环结构#include main() int i=1, j; while ( i = 9 ) printf(%4d, i+ );

12、 printf (n-n); i=1; while ( i= 9 ) j = 1; while ( j = i ) printf (%4d, i*j ); j+; printf (n); i+; printf( (j=i)? “%4dn” : “%4d”, i*j);if ( j=i ) printf(“%4dn”, i*j);else printf(“%4d”, i*j);Recurrent Algorithm (递推算法递推算法)In for statement, comma, works as operator, not separator! Parallel-loop structur

13、e! 并列循环结构并列循环结构Jump StatementsbreakcontinuereturngotoLabeled StatementsidentifiercasedefaultExpr?break;Expr?break;expr2?break;expr3;expr1;Statementafter loopStatementafter loopStatementafter loopNYNYNYwhile-structurefor-structuredo-while-structureOutput:N: 555555Divisor: 777 Output:N: 56789Divisor: 521 Expr?continue;Expr?expr2?expr3;expr1;Statementafter loopStatementafter loopStatementafter loo