Fence Painting (Анализ)

The values $a,b,c$, and $d$ lie in the range from $0$ to $100$. We'll iterate over all possible unit segments from $0$ to $100$ and count how many of them lie completely within the interval $[a;b)$ or the interval $[c;d)$.

Example

Consider the fence painting shown in the example below.

The paint covers $6$ units of the fence, from x = 4 to x = 10.

Algorithm implementation

Read the input data.

scanf("%d %d", &a, &b);
scanf("%d %d", &c, &d);

Iterate over the coordinates from $0$ to $100$. In the variable $res$, count the number of coordinates $i$ that belong to at least one of the intervals $[a;b)$ and $[c;d)$.

res = 0;
for (i = 0; i <= 100; i++)
  if ((a <= i && i < b) || (c <= i && i < d)) res++;

Print the answer.

printf("%d\n", res);