C Primer Plus 第6版 编程练习答案（第六章）
— C Primer Plus, 编程 — 5 min read
6.1.c
#include <stdio.h>int main(void){ char letter[26]; int i; for(i = 0; i < 26; i++) { letter[i] = 'a' + i; printf("%c ", letter[i]); } return 0;}6.2.c
#include <stdio.h>int main(void){ int rows, chars; for(rows = 0; rows < 5; rows++) { for(chars = 0; chars <= rows; chars++) printf("$"); printf("\n"); } return 0;}6.3.c
#include <stdio.h>int main(void){ int i, j; for(i = 0; i < 6; i++) { for(j = 0; j <= i; j++) printf("%c", 'F' - j); printf("\n"); } return 0;}6.4.c
#include <stdio.h>int main(void){ char word = 'A'; int i, j; for(i = 0; i < 6; i++) { for(j = 0; j <= i; j++) printf("%c", word++); printf("\n"); } return 0;}6.5.c
#include <stdio.h>int main(void){ char letter; printf("Please enter a capital letter.\n"); scanf("%c", &letter); const int n = letter - 'A'; int space, j, row; for(space = n, row = 0; space >= 0; space--, row++) { for(j = 0; j < space; j++) { printf(" "); } for(j = 0; j <= row; j++) { printf("%c", 'A' + j); } for(j = row; j > 0; j--) { printf("%c", 'A' + j - 1); } printf("\n"); } return 0;}6.6.c
#include<stdio.h>int main(void){ int n,m; printf("请输入表格开始的数：\n"); scanf("%d",&n); printf("请输入表格结束的数：\n"); scanf("%d",&m);
printf("\n"); printf("原数\t平方\t立方\t\n"); for(n=n; n<=m; n++) printf("%d\t%d\t%d\n",n,n*n,n*n*n); return 0;
}6.7.c
#include <stdio.h>#include <string.h>int main(void){ char word[10]; printf("Please enter a word.\n"); scanf("%s", word); int lenght = strlen(word); int i; for(i = lenght - 1; i >= 0; i--) printf("%c", word[i]); return 0;}6.8.c
#include <stdio.h>int main(void){ float value_1, value_2; printf("Please enter two floating point number(q to quit)\n"); while(scanf("%f %f", &value_1, &value_2) == 2) { float result = (value_1 - value_2) / (value_1 * value_2); printf("result = %f\n", result); printf("Please enter two floating point number(q to quit)\n"); } return 0;}6.9.c
#include <stdio.h>float result(float v1, float v2);int main(void){ float value_1, value_2; printf("Please enter two floating point number(q to quit)\n"); while(scanf("%f %f", &value_1, &value_2) == 2) { printf("result = %f\n", result(value_1, value_2)); printf("Please enter two floating point number(q to quit)\n"); } return 0;}float result(float v1, float v2){ float result = (v1 - v2) / (v1 * v2); return result;}6.10.c
#include <stdio.h>int main(void){ int lower, upper; printf("Enter lower and upper integer limits:"); while(scanf("%d %d", &lower, &upper) == 2 && upper > lower) { int i, sum; sum = 0; for(i = lower; i <= upper; i++) sum += i * i; printf("The sums of the squares from %d to %d is %d\n", lower * lower, upper * upper, sum); printf("Enter next set of limits:"); } printf("Done"); return 0;}6.11.c
#include <stdio.h>#define N 8int main(void){ int i, num[N]; printf("Please enter 8 numbers:\n"); for(i = 0; i < N; i++) scanf("%d", &num[i]); printf("Reverse order printing 8 numbers:\n"); for(i = N - 1; i >= 0; i--) printf("%d ", num[i]); return 0;}6.12.c
#include <stdio.h>int main(void){ int n; printf("Please enter a numbe (0 to quit): "); while(scanf("%d", &n) == 1 && n > 0) { double result_1 = 0.0; double result_2 = 0.0; int i; for(i = 1; i <= n; i++) { result_1 += 1.0 / i; if (i % 2 == 1) result_2 += 1.0 / i; else result_2 -= 1.0 / i; } printf("1.0 + 1.0/2.0 + 1.0/3.0 + 1.0/4.0 + ..."); printf("sum are %g\n", n, result_1); printf("1.0 - 1.0/2.0 + 1.0/3.0 - 1.0/4.0 + ..."); printf("sum are %g\n", n, result_2); printf("Please enter a numbe (0 to quit): "); } return 0;}6.13.c
#include <stdio.h>#define N 8
int main(void){ int a[N], i; int val = 2;
for (i = 0; i < N; i++) { a[i] = val; val *= 2; } i = 0; printf("Here are the results for array:\n", N); do { printf("%d ", a[i++]); } while (i < N); printf("\nDone.\n");
return 0;}6.14.c
#include <stdio.h>#define N 8
int main(void){ int i; double a[N], b[N];
printf("Please enter %d numbers:\n", N); for (i = 0; i < N; i++) scanf("%lf", &a[i]); b[0] = a[0]; for (i = 1; i < N; i++) b[i] = a[i] + b[i - 1]; printf("Here are the results for array a:\n"); for (i = 0; i < N; i++) printf("%-3g", a[i]); printf("\nHere are the results for array b:\n"); for (i = 0; i < N; i++) printf("%-3g", b[i]);
printf("\nDone.\n");
return 0;}6.15.c
#include <stdio.h>#define LEN 255
int main(void){ int i = 0; char input[LEN];
printf("Please enter a string:\n"); do { scanf("%c", &input[i]); } while (input[i] != '\n' && ++i && i < LEN);
printf("Reversing print the string is:\n"); for (i--; i >= 0; i--) printf("%c", input[i]); printf("\nDone.\n");
return 0;}6.16.c
#include <stdio.h>#define RATE_SIMP 0.10#define RATE_COMP 0.05#define INIT_AMT 100.0
int main(void){ int years = 0; double daphne = INIT_AMT; double deirdre = INIT_AMT;
do { daphne += RATE_SIMP * INIT_AMT; deirdre += RATE_COMP * deirdre; years++; } while (deirdre < daphne); printf("Investment values after %d years:\n", years); printf("Daphne: $%.2f\n", daphne); printf("Deirdre: $%.2f\n", deirdre); printf("Deirdre(invest) > Daphne(invest)\n");
return 0;}6.17.c
#include <stdio.h>#define TAX 0.08
int main(void){ int i = 0; double Chuckie = 100.0;
do { i++; Chuckie += Chuckie * TAX; Chuckie -= 10; printf("(%d)account:%g.\n", i, Chuckie); } while (Chuckie > 9); printf("After %d years:\n", ++i); printf("Chuckie has taken all of the money!\n");
return 0;}6.18.c
#include <stdio.h>
int main(void){ int i = 1; int friends = 5;
while (friends < 150) { printf("At %d weeks, Rabnud has", i); printf("%4d friends.\n", friends); friends = 2 * (friends - i++); } printf("At %d weeks, over Dunbar's number(150).\n", i);
return 0;}