Source code for submission s1279

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#include <stdio.h>
#include <algorithm>
#include <string.h>
 
#define debug(format,...) fprintf(stderr, format, __VA_ARGS__)
class Ant;
bool operator< (const Ant&, const Ant &);
 
class Ant {
	public:
		int dir;
		int id;
		int time;
		friend bool operator< (const Ant&, const Ant &);
/*		bool operator<= (const Ant &ant) {
			return this->id <= ant.id;
		}*/
		void reverse(Ant *ant) {
			std::swap<int>(this->time, ant->time);
			this->dir *= -1;
			ant->dir *= -1;
		}
		bool compare(Ant *ant) {
			if(this->dir==1 && ant->dir==-1) {
				this->reverse(ant);
				return true;
			}
			return false;
		}
};
 
bool operator< (const Ant &ant1, const Ant &ant2) {
	return ant1.id < ant2.id;
}
 
 
int main() {
	int positions[100000];
	Ant ant[100000];
	int ants, pos, len, i, j;
	int maxTime=-1, maxAnt1=-1, maxAnt2=-1;
	char dir[3];
	while(scanf("%d %d", &len, &ants)>0) {
		memset(ant, 0, (len+1)*sizeof(Ant));
 
		for(i=0; i<ants; i++) {
			scanf("%d %s", &pos, dir);
			ant[pos].id = pos;
			ant[pos].dir = (dir[0]=='L' ? -1 : 1);
			ant[pos].time = (ant[pos].dir==-1 ? pos : len-pos);
		}
 
		for(i=0,j=0; i<=len; i++) {
			if(i!=j && ant[i].dir) {
				positions[j++]=i;
			}
		}
 
		for(i=0; i<ants-1; i++) {
			j=i;
			while(ant[positions[j]].compare(ant+positions[j+1]) && j>0) {
				if(j==0) {
					break;
				}
				j--;
			}
		}
 
		maxTime = maxAnt2 = -1;
		for(i=0; i<ants; i++) {
			if(ant[positions[i]].time == maxTime) {
				maxAnt2 = ant[positions[i]].id;
			}else if (ant[positions[i]].time > maxTime) {
				maxAnt1 = ant[positions[i]].id;
				maxAnt2 = -1;
				maxTime = ant[positions[i]].time;
			}
		}
		if (maxAnt2 == -1) {
			printf(
				"The last ant will fall down in %d seconds - started at %d.\n",
				maxTime, maxAnt1);
		}else {
			printf(
				"The last ant will fall down in %d seconds - started at %d and %d.\n",
				maxTime, maxAnt1, maxAnt2);
		}
	}
	return 0;
}
 
 

Diff to submission s1234

--- c4.s1234.cteam102.ants.cpp.0.ants.cpp
+++ c4.s1279.cteam102.ants.cpp.0.ants.cpp
@@ -36,4 +36,5 @@
 
 int main() {
+        int positions[100000];
         Ant ant[100000];
         int ants, pos, len, i, j;
@@ -52,6 +53,5 @@
                 for(i=0,j=0; i<=len; i++) {
                         if(i!=j && ant[i].dir) {
-                                memcpy(ant+j,ant+i, sizeof(Ant));
-                                j++;
+                                positions[j++]=i;
                         }
                 }
@@ -59,5 +59,5 @@
                 for(i=0; i<ants-1; i++) {
                         j=i;
-                        while(ant[j].compare(ant+j+1) && j>0) {
+                        while(ant[positions[j]].compare(ant+positions[j+1]) && j>0) {
                                 if(j==0) {
                                         break;
@@ -69,10 +69,10 @@
                 maxTime = maxAnt2 = -1;
                 for(i=0; i<ants; i++) {
-                        if(ant[i].time == maxTime) {
-                                maxAnt2 = ant[i].id;
-                        }else if (ant[i].time > maxTime) {
-                                maxAnt1 = ant[i].id;
+                        if(ant[positions[i]].time == maxTime) {
+                                maxAnt2 = ant[positions[i]].id;
+                        }else if (ant[positions[i]].time > maxTime) {
+                                maxAnt1 = ant[positions[i]].id;
                                 maxAnt2 = -1;
-                                maxTime = ant[i].time;
+                                maxTime = ant[positions[i]].time;
                         }
                 }