PAT preliminary - test

Black box testing

The site is used to brush the question Heihe test the system on a stage and several groups of input data, allowing submit the program to take to run these data, the results to see whether the output of the correct answer exactly .

Black box testing is divided into single-point and multi-point test test

Single point test

The system determines each output data is correct, the correct set of test data, the user can obtain the set of data value.

#include<stdio.h>
int main(){
    int a,b;
    // 这里推荐如果输入是 1空格2这样的形式，scanf也保持 %d空格%d的格式，逗号之类的同理，保持一致。怕出现不必要的问题。我用vscode写代码遇到过这些问题！
    scanf("%d %d",&a,&b);
    printf("%d===%d",a,b);
}

Multi-point testing

Requirements to run a one-time all the data, all of this considered entirely correct output through; as long as there is a set of data output errors, 0 points are scored. PTA test platform with a single point!

Multi-point test code templates

void fn2(){
    int a, b;
    // 获取输入结束时（就是读不到数据，读入数据失败），scanf会返回EOF。EOF是一个数值
    // scanf("%d %d", &a, &b)成功读入两个数据会返回2.读入失败时会返回-1，C语言中用EOF表示-1
    while (scanf("%d %d", &a, &b) != EOF){
        // 处理数据
        printf("%d %d", a, b);
    }
}

//关于EOF的测试
int main()
{
    printf("%d", EOF);
}

PS: We normally write code, the console will not trigger input data is EOF, you can use the shortcut key ctrl + Z, the console appears, and then press Enter ^ Z is triggered. But I'm used to directly Ctrl + C to terminate the program.

Reference books: Algorithms notes