1 files changed, 46 insertions, 0 deletions
diff --git a/šola/aps1/dn/osvetlitev/resitev.cpp b/šola/aps1/dn/osvetlitev/resitev.cpp
new file mode 100644
index 0000000..0a17f31
--- /dev/null
+++ b/šola/aps1/dn/osvetlitev/resitev.cpp
@@ -0,0 +1,46 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+struct event {
+	int pos;
+	bool tip; // true za začetek, false za konec
+};
+int compar_events (const void * a, const void * b) {
+	if (((struct event *) a)->pos == ((struct event *) b)->pos)
+		return 0;
+	if (((struct event *) a)->pos < ((struct event *) b)->pos)
+		return -1;
+	return 1;
+}
+int main (void) {
+	struct event events[20000];
+	int M, N, x, d;
+	scanf("%d %d", &M, &N);
+	for (int i = 0; i < N; i++) {
+		scanf("%d %d", &x, &d);
+		events[2*i].pos = x-d >= 0 ? x-d : 0;
+		events[2*i].tip = true;
+		events[2*i+1].pos = x+d <= M ? x+d : M;
+		events[2*i+1].tip = false;
+	}
+	qsort(events, 2*N, sizeof events[0], compar_events);
+	int osv = 0;
+	int depth = 0;
+	int start;
+	for (int i = 0; i < 2*N; i++) {
+		// fprintf(stderr, "pos=%d\ttip=%d\n", events[i].pos, events[i].tip);
+		if (events[i].tip == true) {
+			if (depth == 0)
+				start = events[i].pos;
+			depth++;
+		}
+		if (events[i].tip == false) {
+			depth--;
+			if (depth == 0)
+				osv += events[i].pos - start;
+		}
+	}
+	if (depth != 0)
+		fprintf(stderr, "depth == %d\n", depth);
+	printf("%d\n", M-osv);
+}