bridge.c

int timeToCrossBridge(int* party, int partySize) {
	if (partySize == 1) return party[0];     // 1 torch, 1 guy, no problem
	if (partySize == 2) return party[1];  	// easy
	if (partySize < 1) return -1;	 	  	// no party :(

	int *p = &party[partySize - 1];  // p moves backwards from slowest
	int *fastest = &party[0];
	int *nextFastest = &party[1];
	int time = 0;
	int slowest = 0;

	int mid = (partySize >> 1) - 1;

	if (party[mid] << 1 > party[mid-1] + party[mid+1])
		time += *(p--);
	else
		time += *nextFastest;  				
	

	while (p != party) {
		time += *fastest; 		     
		fastest = nextFastest;
		time += *p; 	  			
		nextFastest = p--;
	

		if ((*p << 1) > *(p-1) + *(p+1))
			fastest = &party[0];
		else
			if (p-- == party) break;
		
	}

	return time;
}