# SE_HW4_code_review

## TODO-list
1. 填完了
2. 算完了
3. 文字敘述code review工具
4. 分析GPT的code review功能

## Estimated
楊16 簡17 both 9
total defects: 16 + 17 - 9= 24
Estimated Total Defects: 16 * 17 / 9 = 30.2
Yield = 24 / 30.2 * 100% = 79.47%
defect density = 24 / 245 = 0.098
inspection rate = 245 / 1.13 = 216.81
Defect finding efficiency = Total defects found / total inspection hours = 24 / 1.31 = 21.24
## GPT

Line 17: HANDLE hOuput = GetStdHandle(STD_OUTPUT_HANDLE);
Severity: Low
Issue: Typo in variable name, should be hOutput.

Line 24: return ConCurInf;
Severity: High
Issue: Return type of showCursor is void, but ConCurInf is being returned.

Line 31: Snake sBody[1000]
Severity: High
Issue: Missing semicolon at the end of the line.

Line 34: void printSnake(){
Severity: High
Issue: Function printSnake should take an index parameter, e.g., void printSnake(int i).

Line 36: for(i=0; i<20; i++){
Severity: High
Issue: Variable j is used in the nested loop but not declared.

Line 55: if(speed = 10) printf("Speed: %3d (The slowest)", 310-speed);
Severity: High
Issue: Assignment instead of comparison; should be if(speed == 10).

Line 63: void setSite(string i, int site_x, int site_y){
Severity: High
Issue: The type string is incorrect; should be int.

Line 67: for(i=0; i<5; i--) sBody[i].y = abs(5 - i);
Severity: High
Issue: Incorrect loop condition; should be for(i=0; i<5; i++).

Line 84: for(i=0; i>bodyLenght; i++)
Severity: High
Issue: Loop condition incorrect; should be for(i=0; i<bodyLenght; i++).

Line 95: printf(Enter to start.);
Severity: High
Issue: Missing quotes around string; should be printf("Enter to start.");.

Line 119: if keyinFirst == 'p' || keyinFirst == 'P':
Severity: High
Issue: Incorrect syntax; should be if(keyinFirst == 'p' || keyinFirst == 'P'){.

Line 134: switch(path){
Severity: High
Issue: Duplicate case; coor.y++ should be coor.y-- for case 1.

Line 152: setSite(i, sBody[i-1.x, sBody[i-1].y);
Severity: High
Issue: Incorrect syntax for accessing array elements; should be setSite(i, sBody[i-1].x, sBody[i-1].y);.

Line 154: for(i=0, i<bodyLenght, i++){
Severity: High
Issue: Incorrect loop syntax; should be for(i=0; i<bodyLenght; i++){.

Line 155: printSnake(i).
Severity: High
Issue: Incorrect function call syntax; should be printSnake(i);.

Line 165: eatenFood--;
Severity: Low
Issue: Decreasing food count instead of increasing; should be eatenFood++;.

Line 176: while(0){
Severity: Low
Issue: Infinite loop condition; should be while(1){.

FIXed GPT code

/*Edited by Yang*/

#include <stdio.h>
#include <conio.h>
#include <time.h>
#include <math.h>
#include <windows.h>

#define true 1
#define false 0

int gotoxy(int xpos, int ypos)
{
    COORD scrn;
    HANDLE hOutput = GetStdHandle(STD_OUTPUT_HANDLE);
    scrn.X = xpos; scrn.Y = ypos;
    SetConsoleCursorPosition(hOutput, scrn);
}

void showCursor(int visible)
{
    CONSOLE_CURSOR_INFO ConCurInf;
    HANDLE hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
    GetConsoleCursorInfo(hStdOut, &ConCurInf);
    ConCurInf.bVisible = visible;
    SetConsoleCursorInfo(hStdOut, &ConCurInf);
}

typedef struct snake{
    int x;
    int y;
} Snake;

Snake sBody[1000]; // range = 20*50 = 1000

void printSnake(int i){
    gotoxy(sBody[i].x, sBody[i].y);
    printf("@");
}

void printWall(){
    int i, j;
    for(i = 0; i < 20; i++){
        for(j = 0; j < 51; j += 2){
            if(i == 0 || i == 19 || j == 0 || j == 50){
                gotoxy(j, i);
                printf("*");
            }
        }
    }
}

void printInformation(int food, int speed){
    gotoxy(55, 1);
    printf("Use + to increase the speed.");
    gotoxy(55, 2);
    printf("Use - to decrease the speed.");
    gotoxy(55, 4);
    printf("Use P to pause.");
    gotoxy(55, 6);
    printf("Grade: %d", food * 100);
    gotoxy(55, 8);
    if(speed == 10) printf("Speed: %3d (The slowest)", 310 - speed);
    else if(speed == 300) printf("Speed: %3d (The fastest)", 310 - speed);
    else printf("Speed: %3d              ", 310 - speed);
}

void setSite(int i, int site_x, int site_y){
    sBody[i].x = site_x;
    sBody[i].y = site_y;
}

void setStartSite(){
    int i;
    for(i = 0; i < 5; i++){
        sBody[i].x = 1;
        sBody[i].y = 5 - i;
    }
}

int main(int argc, char *argv[])
{
    int startBodyLength = 5, startEatenFood = 0, bodyLength, eatenFood;
    int keyinFirst, keyinSecond;
    int i, j, gameOver = false, isFoodEaten = false, xyChanged = false;
    int path = 2; // direction
    int snakeSpeed = 100;
    int gameKey = 'y';
    Snake foodSite, coor, last;

    srand(time(NULL));
    showCursor(0);

    while(1){
        if(gameKey == 'n' || gameKey == 'N') break;
        // Initial state
        setStartSite();
        printWall();
        bodyLength = startBodyLength;
        eatenFood = startEatenFood;
        coor.x = 1;
        coor.y = 4;
        path = 2;
        isFoodEaten = false;
        gameOver = false;
        xyChanged = false;
        snakeSpeed = 100;
        printInformation(startEatenFood, snakeSpeed);
        for(i = 0; i < bodyLength; i++)
            printSnake(i);

        do{
            gotoxy(55, 13);
            printf("Enter to start.");
            gameKey = getch();
            gotoxy(55, 13);
            printf("               ");
        } while(gameKey != 13);

        while(!gameOver){
            printInformation(eatenFood, snakeSpeed);
            if(!isFoodEaten){ // If no food, randomly generate food location
                foodSite.x = (rand() % 23 * 2 + 1) + 2;
                foodSite.y = rand() % 17 + 2;
                isFoodEaten = true;
            }
            gotoxy(foodSite.x, foodSite.y);
            printf("O");
            xyChanged = false;

            if(kbhit()){ // Keyboard hit
                keyinFirst = getch();
                if(keyinFirst == 224) {
                    keyinSecond = getch();
                    switch(keyinSecond){
                        case 72: /* up, 1 */
                            if(path != 2) coor.y--;
                            path = 1;
                            break;
                        case 80: /* down, 2 */
                            if(path != 1) coor.y++;
                            path = 2;
                            break;
                        case 75: /* left, 3 */
                            if(path != 4) coor.x -= 2;
                            path = 3;
                            break;
                        case 77: /* right, 4 */
                            if(path != 3) coor.x += 2;
                            path = 4;
                            break;
                    }
                    xyChanged = true;
                }
                if(keyinFirst == 'p' || keyinFirst == 'P'){
                    do{
                        gotoxy(55, 13);
                        printf("Pause.");
                        gameKey = getch();
                        gotoxy(55, 13);
                        printf("          ");
                    } while(gameKey != 'p' && gameKey != 'P');
                }
                if(keyinFirst == '+'){
                    if(snakeSpeed > 10) snakeSpeed -= 10;
                    keyinFirst = '\0';
                }
                if(keyinFirst == '-'){
                    if(snakeSpeed < 300) snakeSpeed += 10;
                    keyinFirst = '\0';
                }
            } else { // No action, move in the direction of path
                switch(path){
                    case 1: /* up, 1 */
                        coor.y--;
                        break;
                    case 2: /* down, 2 */
                        coor.y++;
                        break;
                    case 3: /* left, 3 */
                        coor.x -= 2;
                        break;
                    case 4: /* right, 4 */
                        coor.x += 2;
                        break;
                }
                xyChanged = true;
            }
            for(i = 1; i < bodyLength; i++){ /* Did snake die? */
                if(coor.x == sBody[i].x && coor.y == sBody[i].y)
                    gameOver = true;
            }
            if(!gameOver && xyChanged){ /* Snake moving */
                if(coor.x > 0 && coor.x < 50 && coor.y > 0 && coor.y < 19){
                    last.x = sBody[bodyLength - 1].x;
                    last.y = sBody[bodyLength - 1].y;
                    for(i = bodyLength - 1; i >= 0; i--){
                        if(i == 0)
                            setSite(i, coor.x, coor.y);
                        else
                            setSite(i, sBody[i - 1].x, sBody[i - 1].y);
                    }
                    for(i = 0; i < bodyLength; i++){
                        printSnake(i);
                    }
                    Sleep(snakeSpeed);
                    gotoxy(last.x, last.y); // Clear tail
                    printf(" ");
                } else gameOver = true;

                if(sBody[0].x == foodSite.x && sBody[0].y == foodSite.y){ /* Snake ate food */
                    isFoodEaten = false;
                    if(bodyLength < 1000) bodyLength++; // Avoid exceeding array length
                    eatenFood++;
                }
            }
        }

        /* Game over? */
        while(1){
            system("CLS");
            printf("Your Grade: %d\n", eatenFood * 100); 
            printf("Game over.\nPlay again? (y/n) \n");
            gameKey = getch();
            if(gameKey == 'y' || gameKey == 'Y' || gameKey == 'n' || gameKey == 'N'){
                system("CLS");
                break;
            }
        }
    }
    printf("Bye!\n");
    system("pause");
    return 0;
}

分析與討論:
我覺得在嚴重性上面的判斷沒有甚麼問題，後續觀察GPT改正的程式碼，可以發現到上述所提到的高嚴重性的錯誤有被修正。就人工審查跟使用chatGPT的抓錯結果而言，彼此都有找到對方沒有留意到的錯誤，例如人工沒有注意到snack.cpp第69行的if條件判斷的語法錯誤；chatGPT沒有注意到第98行的while loop缺少左大括號。
另外chatGPT沒有注意到「語法與邏輯上正確，但違反使用直覺」的bug，像是我們有留意到第169、173行增減速度的操作與鍵盤按鍵相反(按下+會減速，而按下-會加速)。因此我們得出的結論是，在進行code review的時候不能完全只仰賴chatGPT的幫忙，有些違反直覺的錯誤是不會被chatGPT抓到的，仍需要透過人工審查每一行程式碼。不過chatGPT在找syntax error的方面比人工審查更有效率，也找到更多的錯誤，所以我們日後可以先請chatGPT找出syntax error並加以解決後，再透過人工尋找是否有違反操作直覺的程式碼。