C Review

Review

How review works

Ideas you missed in a checkpoint come back here a day later, then again a few days after that. A couple of short problems each. Coming back to them after a gap is what makes them stick.

    Back to the course
      problem.c to run
      #include <stdio.h>

int main(void) {
    int s;
    for (int i = 0; i < 3; i++) {
        scanf("%d", &s);
        if (s = 100) {
            printf("%d: gold\n", s);
        } else {
            printf("%d: keep going\n", s);
        }
    }
    return 0;
}
      problem.c to run
      #include <stdio.h>

int main(void) {
    for (int i = 1; i <= 15; i++) {
        printf("%d\n", i);
    }
    return 0;
}
      problem.c to run
      #include <stdio.h>

int main(void) {
    int n;
    scanf("%d", &n);
    // count down here
    return 0;
}
      problem.c
      #include <stdio.h>

int main(void) {
    int slices = 7;
    int people = 2;
    double share = slices / people;
    printf("%.1f\n", share);
    printf("%.1f\n", (double)slices / people);
    printf("%d\n", -slices / people);
    printf("%d\n", (int)2.99);
    return 0;
}
      problem.c to run
      #include <stdio.h>

int main(void) {
    printf("char: %zu\n", sizeof(char));
    return 0;
}
      problem.c to run
      #include <stdio.h>

int main(void) {
    // declare level, rank and score here

    printf("Level ?, rank ?, score ?\n");
    return 0;
}
      problem.c to run
      #include <stdio.h>

int main(void) {
    unsigned char fuel = 250;
    // add 10, then print
    printf("%u\n", fuel);
    return 0;
}
      problem.c to run
      #include <stdio.h>

int main(void) {
    printf("%d = %d\n", 10, 10);
    return 0;
}
      problem.c to run
      #include <stdio.h>

int count_ones(unsigned char x) {
    int count = 0;
    return count;
}

int main(void) {
    printf("0 has %d one bits\n", count_ones(0));
    printf("5 has %d one bits\n", count_ones(5));
    printf("170 has %d one bits\n", count_ones(170));
    printf("255 has %d one bits\n", count_ones(255));
    return 0;
}
      problem.c to run
      #include <stdio.h>

int main(void) {
    int lives = 3
    int coins = 120;
    printf("lives %d, coins %d\n", lives, coins);
    return 0;
}
      problem.c to run
      int main(void) {
    int level = 4;
    printf("Level %d\n", level);
    return 0;
}
      problem.c to run
      #include <stdio.h>

int main(void) {
    int total = add_tax(200);
    printf("total %d\n", total);
    return 0;
}

int add_tax(int pence) {
    return pence + pence / 5;
}
      problem.c
      #include <stdio.h>

int level_up(int level) {
    level = level + 1;
    return level * 10;
}

int split_loot(double gold) {
    return gold / 2;
}

void join_party(int size) {
    if (size >= 4) {
        printf("party full\n");
        return;
    }
    printf("joined, party of %d\n", size + 1);
}

int main(void) {
    int level = 3;
    int reward = level_up(level);
    printf("%d %d\n", level, reward);
    printf("%d\n", split_loot(7.0));
    join_party(2);
    join_party(4);
    return 0;
}
      problem.c to run
      #include <stdio.h>

int add_combo_bonus(int score, int combo) {
    if (combo >= 10) {
        score = score + combo * 5;
    }
    return score;
}

int main(void) {
    int score = 200;
    add_combo_bonus(score, 12);
    printf("after a 12-hit combo: %d\n", score);
    add_combo_bonus(score, 3);
    printf("after a 3-hit combo: %d\n", score);
    return 0;
}
      problem.c to run
      #include <stdio.h>

int damage(int attack, int armour) {
    return 0;
}

int main(void) {
    printf("goblin hits the knight for %d\n", damage(12, 9));
    printf("dragon hits the knight for %d\n", damage(40, 9));
    printf("bat hits the knight for %d\n", damage(3, 9));
    return 0;
}
      C, 32-bit: int and pointers are 4 bytes