菜学C++ Day33

• P86例4-11求二维数组各元素及外围元素的和

  #include
  using namespace std;
  //用元素指针求元素之和
  int sum1(int* p, int n1) {
  	int sum = 0;
  	for (int i = 0; i < n1; i++)
  		sum += p[i];
  	return sum;
  }
  //用行指针求外围元素（二维数组外面一周数据）的和
  int sum2( int( *p )[ 5 ], int n2) {
  	int sum = 0;
  	for (int i = 0; i < n2; i++)
  		for (int j = 0; j < 5; j++)
  			if (i == 0 || i == n2 - 1 || j == 0 || j == 4)
  				sum += p[i][j];
  	return sum;
  }
  //用行指针输出二维数组
  void output(int p[][5], int n2) {
  	for (int i = 0; i < n2; i++) {
  		for (int j = 0; j < 5; j++)
  			cout << *(p[i] + j) << 't';
  		cout << endl;
  	}
  }
  
  int main() {
  	int b[3][5] = { {2,5,8,6,1},{4,12,9,5,9},{7,3,11,9,10} };
  	output(b, 3);
  	cout << "外围元素的和为：" << sum1(&b[0][0],3*5) << endl;
  	cout << "所有元素的和为：" << sum2(&b[0], 3) << endl;
  	return 0;
  }

   

  结果：
  

 本来打算多写一点的，因为已经把很不熟悉的二维数组及指针学完了，不过看时间还是明天吧