c语言第六章(苏小红版)资料

1、哈尔滨工业大学哈尔滨工业大学计算机科学与技术学院计算机科学与技术学院苏小红苏小红2021-12-92/622021-12-93/62如何确定如何确定程序的输程序的输入和输出入和输出呢呢?Draw a flowchart for the following problem:读入读入5个整数，计算并显示它们的和个整数，计算并显示它们的和.Input : 5 个整数个整数n1, n2, n3, n4, n5 Output: n1, n2, n3, n4, n5的和的和Input example: 2 3 4 5 6Output example: 202021-12-94/62Input n1Inpu

2、t n2Input n3input n4input n5output sumsum n1+n2+n3+n4+n5n1Assume input example: 2 3 4 5 6n2n3n4n5sumend使用了使用了6个不同的变量个不同的变量start2021-12-95/621, 2, 3, 4, , 4, 3, 2, 12021-12-96/62counter 1, sum 0counter6sum sum + nfalsetruecounter+output suminput n1countersum01 6true2n0 + 2222 6true32 + 3533 6true45 +

3、 4944 6true59 + 51455 6true614 + 62066 6falsecounter-controlled 计数器每次增计数器每次增1使用了使用了3个变量个变量Assume input example: 2 3 4 5 6startend2021-12-97/62step nstep xfalsetrue2021-12-98/62n当型循环当型循环Condition is tested first n计数控制计数控制Loop is controlled by a counternSyntax (initial value ; condition; update counte

4、r) statement;Or (initial value ; condition; update counter) statement;statement; 复合语句复合语句compound statement被当做一条语句看待被当做一条语句看待循环变量控制循环次循环变量控制循环次数，不要在循环体内数，不要在循环体内改变这个变量的值改变这个变量的值2021-12-99/62i 0, sum 0i 5sumsum+ nfalsetruei+output suminput nint i, sum, n;sum = 0;for (i = 0; i 5; i+) scanf(“%d”, &

5、n);sum = sum + n;printf(“%d”, sum);startend2021-12-910/62假假真真真真假假假2021-12-911/62 当型循环当型循环Condition is tested first 条件或计数控制条件或计数控制 Loop is controlled by condition or a counter 语法语法 Or2021-12-912/62n直到型循环直到型循环Statements in the loop are executed first (at least once), and condition is tested lastn条件或计数

6、控制条件或计数控制 Loop is controlled by condition or a counter n语法语法2021-12-913/622021-12-914/62sum = 0的作用？的作用？ 2021-12-915/622021-12-916/62循环条件第一次就为假（如循环条件第一次就为假（如输入输入1）时会怎样？）时会怎样？2021-12-917/62真真假假假假 Testing Condition First2021-12-918/62假真真假假Testing condition last 2021-12-919/622021-12-920/622021-12-921/6

7、22021-12-922/62循环起始条件循环起始条件循环变量增值循环变量增值循环结束条件循环结束条件2021-12-923/622021-12-924/622021-12-925/62利用前项利用前项计算后项计算后项2021-12-926/62每次单独计算每次单独计算累加项累加项2021-12-927/622021-12-928/622021-12-929/62想一个想一个1100之间的数之间的数猜对猜对: right!猜错猜错: :wrong!并提示并提示大小大小2021-12-930/622021-12-931/622021-12-932/622021-12-933/622021-12-

8、934/622021-12-935/622021-12-936/622021-12-937/622021-12-938/622021-12-939/622021-12-940/622021-12-941/62?退出一层退出一层循环或循环或switch?中断此次中断此次循环，开始下一次循环，开始下一次2021-12-942/62n?10Please enter n:10n = 10Please enter n: -10Program is over!-102021-12-943/62n?10Please enter n:10n = 10Please enter n: -10Please enter n:20n = 20Please enter n: -20Please enter n:30n = 30Program is over!-1020-20302021-12-944/622021-12-945/622021-12-946/62“瞎猫碰死耗子瞎猫碰死耗子”2021-12-947/62“死循环死循环”2021-12-948/622021-12-949/622021-12-950/62标准库函数，标准库函数，作用是终止整作用是终止整个程序的执行，个程序的执行，强制返回操作强制返回操作系统系统 2021-12-951/62结构清晰的结构清晰的程序程序2021-12-952/6