我正在尝试查找二维数组(方阵)中负数的计数。在矩阵中,如果您从上到下并向左书写数字增加。这里的逻辑是从最后一列开始并向左移动。如果找到负数,则增加行索引并以相同的方式进行直到最后一行。我在 java 代码中收到错误,但在 python 中没有。
public class O_n
{
public static void main(String[] args)
{
int firstarray[][] = {{-2,-1,0},{-1,0,1},{0,1,2}};
int secondarray[][] = {{-4,-3,-2},{-3,-2,-1},{-2,-1,0}};
System.out.print ("First array has"+count_neg(firstarray));
System.out.println("negative numbers");
System.out.print ("Second array has"+count_neg(secondarray));
System.out.println("negative numbers");
}
public static int count_neg(int x[][]){
int count = 0;
int i = 0; //rows
int j = x.length - 1; //columns
System.out.println("max column index is: "+j);
while ( i >=0 && j<x.length){
if (x[i][j] < 0){ // negative number
count += (j + 1);// since j is an index...so j + 1
i += 1;
}
else { // positive number
j -= 1;
}
}
return (count);
}
}
我得到这个输出
max column index is: 2
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1
at O_n.count_neg(O_n.java:22)
at O_n.main(O_n.java:9)
/home/eos/.cache/netbeans/8.1/executor-snippets/run.xml:53: Java
returned: 1
BUILD FAILED (total time: 0 seconds)
这段代码有什么问题?同样的事情在 python 中工作...
def count_neg(array):
count = 0
i = 0 # row
j = len(array) -1 # col
# since we are starting from right side
while j >= 0 and i < len(array):
if array[i][j] < 0:
count += (j + 1)
i += 1
else:
j -= 1
return count
print(count_neg([[-4,-3,-1,1],[-2,-2,1,2],[-1,1,2,3],[1,2,4,5]]))
最佳答案
我会这样写方法,只要遍历二维数组并在每次找到负数时增加count
public static int count_neg(int x[][]){
int count = 0;
for(int i = 0; i < x.length; i++){
for(int j = 0; j < x[i].length; j++){
if(x[i][j] < 0){
count++;
}
}
}
return (count);
}
关于java - 计算数组中的负数,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/50662932/