实验4

任务1

#include <stdio.h>
#define N 4
#define M 2
void test1() {
int x[N] = { 1, 9, 8, 4 };
int i;
printf("sizeof(x) = %d\n", sizeof(x));
for (i = 0; i < N; ++i)
printf("%p: %d\n", &x[i], x[i]);
printf("x = %p\n", x);
}
void test2() {
int x[M][N] = { {1, 9, 8, 4}, {2, 0, 4, 9} };
int i, j;
printf("sizeof(x) = %d\n", sizeof(x));
for (i = 0; i < M; ++i)
for (j = 0; j < N; ++j)
printf("%p: %d\n", &x[i][j], x[i][j]);
printf("\n");
printf("x = %p\n", x);
printf("x[0] = %p\n", x[0]);
printf("x[1] = %p\n", x[1]);
printf("\n");
}
int main() {
printf("测试1: int型一维数组\n");
test1();
printf("\n测试2: int型二维数组\n");
test2();
return 0;
}

问题1：是，相同
问题2：是，相同，16，字节数

任务2

#include <stdio.h>
#define N 100
void input(int x[], int n);
double compute(int x[], int n);
int main() {
int x[N];
int n, i;
double ans;
while (printf("Enter n: "), scanf_s("%d", &n) != EOF) {
input(x, n);
ans = compute(x, n);
printf("ans = %.2f\n\n", ans);
}
return 0;
}
void input(int x[], int n) {
int i;
for (i = 0; i < n; ++i)
scanf_s("%d", &x[i]);
}
double compute(int x[], int n) {
int i, high, low;
double ans;
high = low = x[0];
ans = 0;
for (i = 0; i < n; ++i) {
ans += x[i];
if (x[i] > high)
high = x[i];
else if (x[i] < low)
low = x[i];
}
ans = (ans - high - low) / (n - 2);
return ans;
}

问题1：形参：要指定数组类型和长度，实参：直接用数组名，
问题2：读取并存入数据，求平均值

任务3

#include <stdio.h>
#define N 100
void output(int x[][N], int n);
void init(int x[][N], int n, int value);
int main() {
int x[N][N];
int n, value;
while (printf("Enter n and value: "), scanf_s("%d%d", &n, &value) != EOF) {
init(x, n, value);
output(x, n);
printf("\n");
}
return 0;
}
void output(int x[][N], int n) {
int i, j;
for (i = 0; i < n; ++i) {
for (j = 0; j < n; ++j)
printf("%d ", x[i][j]);
printf("\n");
}
}
void init(int x[][N], int n, int value) {
int i, j;
for (i = 0; i < n; ++i)
for (j = 0; j < n; ++j)
x[i][j] = value;
}

问题1：形参：用数组名，实参：指定数组类型和长度
问题2：不能
问题3:输出元素，初始化值

任务4

#include <stdio.h>
#define N 100
void input(int x[N], int n);
double median(int x[N], int n);
int main() {
int x[N];
int n;
double ans;
while (printf("Enter n: "), scanf_s("%d", &n) != EOF) {
input(x, n);
ans = median(x, n);
printf("ans = %g\n\n", ans);
}
return 0;
}
void input(int x[], int n) {
int i;
for (i = 0; i < n; ++i)
scanf_s("%d", &x[i]);
}

void order(int x[], int n) {
int i, j, w;
for (i = 0; i < n - 1; i++) {
for (j = 0; j < n - 1; j++) {
if (x[j] > x[j + 1]) {
w = x[j];
x[j] = x[j + 1];
x[j + 1] = w;
}
}
}
}

double median(int x[], int n) {
order(x, n);
if (n % 2 == 0)
return (x[n / 2 - 1] + x[n / 2]) / 2.0;
else
return x[n / 2];
}

作业5

#include <stdio.h>
#define N 100
void input(int x[][N], int n);
void output(int x[][N], int n);
void rotate_to_right(int x[][N], int n);
int main() {
int x[N][N];
int n;
printf("Enter n: ");
scanf_s("%d", &n);
input(x, n);
printf("原始矩阵:\n");
output(x, n);
rotate_to_right(x, n);
printf("变换后矩阵:\n");
output(x, n);
return 0;
}
void input(int x[][N], int n) {
int i, j;
for (i = 0; i < n; ++i) {
for (j = 0; j < n; ++j)
scanf_s("%d", &x[i][j]);
}
}
void output(int x[][N], int n) {
int i, j;
for (i = 0; i < n; ++i) {
for (j = 0; j < n; ++j)
printf("%4d", x[i][j]);
printf("\n");
}
}
void rotate_to_right(int x[][N], int n) {
int a[N];
for (int i = 0; i < n; ++i) {
a[i] = x[i][n - 1];
}
for (int j = n - 1; j > 0; --j) {
for (int i = 0; i < n; ++i) {
x[i][j] = x[i][j - 1];
}
}
for (int i = 0; i < n; ++i) {
x[i][0] = a[i];
}
}

作业6

#include <stdio.h>
#include<math.h>
#define N 100
void dec_to_n(int x, int n);
int main() {
int x;
while (printf("输入十进制整数: "), scanf_s("%d", &x) != EOF) {
dec_to_n(x, 2);
dec_to_n(x, 8);
dec_to_n(x, 16);
printf("\n");
}
return 0;
}
void dec_to_n(int x, int n) {
char syb[] = "0123456789ABCDEF";
char w[N];
int t, j, i = 0;

while (x > 0) {
    t = x % n;
    w[i++] = syb[t];
    x = x / n;
}


for (j = i - 1; j >= 0; j--) {
    printf("%c", w[j]);
}
printf("\n");

}

作业7

#include <stdio.h>
#define N 100
void input(int x[][N], int n);
void output(int x[][N], int n);
int is_magic(int x[][N], int n);
void b_sort(int x[], int n);
int main() {
int x[N][N];
int n;
while (printf("输入n: "), scanf_s("%d", &n) != EOF) {
printf("输入方阵:\n");
input(x, n);
printf("输出方阵:\n");
output(x, n);
if (is_magic(x, n))
printf("是魔方矩阵\n\n");
else
printf("不是魔方矩阵\n\n");
}
return 0;
}
void input(int x[][N], int n) {
int i, j;
for (i = 0; i < n; ++i) {
for (j = 0; j < n; ++j)
scanf_s("%d", &x[i][j]);
}
}
void output(int x[][N], int n) {
int i, j;
for (i = 0; i < n; ++i) {
for (j = 0; j < n; ++j)
printf("%4d", x[i][j]);
printf("\n");
}
}
int is_magic(int x[][N], int n) {
int i, j;
int sum, sum1;
sum1 = 0;
for (j = 0; j < n; j++) {
sum1 += x[0][j];
}
for (i = 0; i < n; i++) {
sum = 0;
for (j = 0; j < n; j++) {
sum += x[i][j];
}
if (sum != sum1) {
return 0;
}
}
for (j = 0; j < n; j++) {
sum = 0;
for (i = 0; i < n; i++) {
sum += x[i][j];
}
if (sum != sum1) {
return 0;
}
}
sum = 0;
for (i = 0; i < n; i++) {
sum += x[i][i];
}
if (sum != sum1) {
return 0;
}
sum = 0;
for (i = 0; i < n; i++) {
sum += x[i][n - 1 - i];
}
if (sum != sum1) {
return 0;
}
return 1;
}