Black box test - data reading and output mode

One 、 Three input types of multipoint testing

1、while···EOF type

The title does not give an end condition for input , By default, the end of the file is read . You can use scanf Whether the return value of is EOF To determine whether the input is over .

while(scanf("%d",&n)!=EOF){
    
        
    }

The meaning of the code ： as long as scanf The return value of is not EOF（ The data in the file has not been read ） Just read it again and again n, perform while The content in , Exit when reading into the end of the file while loop .

2、while···break type

It is required to stop the input when the input data meets a certain condition .
The first way to write it ： stay while···EOF Internal judgment , When the exit conditions are met, interrupt the current while loop

int a,b;
    while(scanf("%d%d",&a,&b)!=EOF)
    {
    
        if(a==0&&b==0)
        {
    
            break;
        }
    }

The second way ： Put the judgment of exit conditions in while In the sentence , Make it relate to scanf Separated by commas ：

int a,b;
    while(scanf("%d%d",&a,&b),a||b)//a,b There is one for 0 Quit 
    {
    
        
    }

3、while（T- -） type

Give the number of groups of test data , Then the corresponding amount of output data is given , Variable for group number T To record , A total of T Secondary cycle .

int T;
    scanf("%d" ,&T);
    while(T--)
    {
    
        scanf("%d",&a);
    }

Two 、 Three common output types

1、 Normal output

2、 Each group of data output is followed by an additional blank line

Just add a line feed

3、 There is a blank line between the two sets of output data , There is no blank line after the last set of data

This usually appears in while（T- -） Under the circumstances , Just by judgment T Whether it has been reduced to 0 Determine whether additional line breaks should be output .

int T;
    scanf("%d" ,&T);
    while(T--)
    {
    
        scanf("%d",&a);
        if(T>0)
        {
    
        	printf('\n');
        }
    }

Similar requirements ： Output one line N It's an integer , Every two numbers are separated by a space , There is no space after the last number .

for(int i=0;i<n;i++)
    {
    
        printf("%d",a[i]);
        if(i<n-1)printf(" ");
        else{
    
            printf("\n");
        }
    }

The last thing to note is this , In multipoint testing , Every time the loop resets the variables and arrays （ Reset array usage memset or fill function ）, Otherwise, when the next data comes, the state of variables and arrays will not be the initial state .