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 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("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");
        else
            printf("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;
}