Dare2Solve
The problem involves determining the winner of a Senate voting game between two parties: "Radiant" (R) and "Dire" (D). Each senator in the Senate has a chance to eliminate an opponent senator in each round. The goal is to find out which party will win, given that senators with fewer votes will be eliminated, and the remaining senators will continue the process.
To solve this problem, we need to simulate the elimination process by keeping track of the positions of the senators from each party. By using two queues, we can effectively manage the turn-based elimination process and determine the winner.
Initialization:
radiant
for "R" senators and dire
for "D" senators.Populate Queues:
Simulation:
Determine the Winner:
radiant
queue is empty, "Dire" wins. Otherwise, "Radiant" wins.O(n), where n is the length of the senate
string. Each senator is processed a constant number of times (adding and removing from the queue).
O(n), where n is the length of the senate
string. We store all the indices in the queues.
class Solution {
public:
string predictPartyVictory(string senate) {
deque<char> dq(senate.begin(), senate.end());
while (!dq.empty()) {
char first = dq.front();
dq.pop_front();
int len = dq.size();
bool foundOpponent = false;
for (int i = 0; i < len; ++i) {
if (first != dq[i]) {
dq.erase(dq.begin() + i);
dq.push_back(first);
foundOpponent = true;
break;
}
}
if (!foundOpponent) {
return (first == 'D') ? "Dire" : "Radiant";
}
}
return ""; // Should never reach here
}
};
class Solution:
def predictPartyVictory(self, senate: str) -> str:
radiant = deque()
dire = deque()
# Populate the queues with indices of senators
for i, char in enumerate(senate):
if char == 'R':
radiant.append(i)
else:
dire.append(i)
# Simulate the process
while radiant and dire:
r_index = radiant.popleft()
d_index = dire.popleft()
# The senator with the smaller index will be eliminated
if r_index < d_index:
radiant.append(r_index + len(senate))
else:
dire.append(d_index + len(senate))
# Determine the winner
return "Dire" if not radiant else "Radiant"
public class Solution {
public String predictPartyVictory(String senate) {
Queue<Integer> radiant = new LinkedList<>();
Queue<Integer> dire = new LinkedList<>();
// Populate the queues with indices of senators
for (int i = 0; i < senate.length(); i++) {
if (senate.charAt(i) == 'R') {
radiant.add(i);
} else {
dire.add(i);
}
}
// Simulate the process
while (!radiant.isEmpty() && !dire.isEmpty()) {
int rIndex = radiant.poll();
int dIndex = dire.poll();
// The senator with the smaller index will be eliminated
if (rIndex < dIndex) {
radiant.add(rIndex + senate.length());
} else {
dire.add(dIndex + senate.length());
}
}
// Determine the winner
return radiant.isEmpty() ? "Dire" : "Radiant";
}
}
var predictPartyVictory = function(senate) {
senate = senate.split('');
while(senate.length) {
var first = senate.shift();
var len = senate.length;
for(var i=0; i<len; i++) {
if(first != senate[i]) {
senate.splice(i, 1);
senate.push(first);
break;
}
}
if(i == len) {
return first == 'D' ? 'Dire' : 'Radiant';
}
}
};