task4

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1.1 连续，相同

       1.2 连续，相同，16，4个数占据的字节

#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("%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("%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2.1 input(int x[], int n)和input(x, n)

       2.2输入n个整数到数组x，算出数组中不算最大值和最小值的平均值

#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("%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3.1output(int x[][N], int n）和output(x, n)

       3.2不能

       3.3把数组中n行n列的元素全设为value，输出数组中n*n的元素

#include <stdio.h>
#define N 100
void input(int x[], int n);
double median(int x[], int n);int main() {int x[N];int n;double ans;while (printf("Enter n: "), scanf("%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("%d", &x[i]);}
}double median(int x[], int n) {int i,j ,temp ;for (i = 0; i < n - 1; i++) {for ( j = 0; j < n - 1 - i; ++j) {if (x[j] > x[j + 1]) {temp = x[j];x[j] = x[j + 1];x[j + 1] = temp;}}}if (n % 2 == 1) { return x[n / 2];} else {return (x[n / 2 - 1] + x[n / 2]) / 2.0;}
}

#include <stdio.h>
#include<stdlib.h>
#define N 100void 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("输入n: ");scanf("%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);system("pause");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("%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 i, j;int temp;for (i = 0; i < n; ++i) {temp = x[i][n - 1];for (j = n - 1; j > 0; --j) {x[i][j] = x[i][j - 1];}x[i][0] = temp;}
}

#include <stdio.h>
#define N 100
void dec_to_n(int x, int n); // 函数声明

int main() {
int x;

while(printf("输入十进制整数: "), scanf("%d", &x) != EOF) {
dec_to_n(x, 2); // 函数调用: 把x转换成二进制输出
dec_to_n(x, 8); // 函数调用: 把x转换成八进制输出
dec_to_n(x, 16); // 函数调用: 把x转换成十六进制输出

printf("\n");
}

return 0;
}

void dec_to_n(int x, int n) {
int remainders[N];
int i = 0, j;
int temp = x;

if (temp == 0) {
printf("0\n");
return;
}

while (temp > 0) {
remainders[i] = temp % n;
temp = temp / n;
i++;
}

for (j = i - 1; j >= 0; j--) {
if (n == 16 && remainders[j] >= 10) {
printf("%c", remainders[j] - 10 + 'A');
} else {
printf("%d", remainders[j]);
}
}
printf("\n");
}

#include <stdio.h>
#define N 100// 函数声明
void input(int x[][N], int n);
void output(int x[][N], int n);
int is_magic(int x[][N], int n);int main() {int x[N][N];int n;while(printf("输入n: "), scanf("%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");elseprintf("不是魔方矩阵\n\n");}return 0;
}// 函数定义
// 功能: 输入一个n*n的矩阵x
void input(int x[][N], int n) {int i, j;for (i = 0; i < n; ++i) {for (j = 0; j < n; ++j)scanf("%d", &x[i][j]);}
}// 功能: 输出一个n*n的矩阵x
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, target;target = n * (n * n + 1) / 2;for (i = 0; i < n; ++i) {sum = 0;for (j = 0; j < n; ++j) {sum += x[i][j];}if (sum != target)return 0;}for (j = 0; j < n; ++j) {sum = 0;for (i = 0; i < n; ++i) {sum += x[i][j];}if (sum != target)return 0;}sum = 0;for (i = 0; i < n; ++i) {sum += x[i][i];}if (sum != target)return 0;sum = 0;for (i = 0; i < n; ++i) {sum += x[i][n - 1 - i];}if (sum != target)return 0;return 1;
}