/4.1/
#include<stdio.h> int main(){ int a[2][3] = {{1,2,3},{4,5,6}}; char b[2][3] = {{'1','2','3'},{'4','5','6'}}; int i,j; for(i = 0;i < 2; ++i) for(j = 0;j < 3; ++j) printf("%x: %d\n",&a[i][j],a[i][j]); printf("\n"); for(i = 0;i < 3; ++i) for(j = 0;j < 3; ++j) printf("%x: %c\n",&b[i][j],b[i][j]); }
1.是按行连续存放,每个元素占四个字节。2.是按行连续存放,每个元素占一个字节。
/4.2/
#include <stdio.h> #define N 1000 int fun(int n, int m, int bb[N]) { int i, j, k = 0, flag; for (j = n; j <= m; j++) { flag = 1; for (i = 2; i < j; i++) if (j%i==0) { flag = 0; break; } if (flag==1) bb[k++] = j; } return k; } int main() { int n = 0, m = 0, i, k, bb[N]; scanf("%d", &n); scanf("%d", &m); for (i = 0; i < m - n; i++) bb[i] = 0; k = fun(n,m,bb); for (i = 0; i < k; i++) printf("%4d", bb[i]); return 0; }
/4.3/
#include <stdio.h> const int N = 5; int find_max(int x[], int n); void input(int x[], int n); void output(int x[], int n); int main() { int a[N]; int max; input(a, N); output(a,N); max = find_max(a, N); printf("max = %d\n", max); return 0; } void input(int x[], int n) { int i; for (i = 0; i < n; ++i) scanf("%d", &x[i]); } void output(int x[], int n) { int i; for (i = 0; i < n; ++i) printf("%d ", x[i]); printf("\n"); } int find_max(int x[],int n) { int max = x[0]; int i; for(i = 1;i < n;i++){ if(x[i]>x[i-1]) max = x[i]; } return max; }
/4.4/
#include <stdio.h> #include<math.h> void dec2n(int x, int n); int main() { int x; printf("输入一个十进制整数: "); scanf("%d", &x); dec2n(x, 2); dec2n(x, 8); dec2n(x, 16); return 0; } void dec2n(int x,int n) { int e,d[100]; int a,b = 0,i = 0; if(n<16) { while(x) { a = x%n; x = x/n; b = b + a*pow(10,i); i++; } printf("%d\n",b); } else{ int c[16] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'}; while(x){ e = x%16; d[i++] = e; x = x/16; } for(i=i-1;i>=0;i--){ printf("%c",c[d[i]]); } } }
/4.5/
#include<stdio.h> #define num(n) (n*n) int main(){ int i,n,j,x=0,y; printf("Enter n:"); while(scanf("%d",&n)!=EOF){ for(i=1;i<=n;i++){ y = 1; x = 0; for(j=1;j<=n;j++){ if(y<=i) { x = x + 1; printf("%d ",x); y++; } else printf("%d ",x); } printf("\n"); } printf("\n"); printf("Enter n:"); } }