#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
using std::vector;
/*
FUNCTION: getRanks
-------------------
Computes competition-style ranks for a vector of numbers.
Ranking rules (Competition Ranking):
------------------------------------
- Highest value gets rank 1
- Equal values share the same rank
- Next rank increases by the number of equal values
Example:
Values: 88, 4, 19, 4, 1, 31, 14, 1, 93, 17
Ranks: 2, 7, 4, 7, 9, 3, 6, 9, 1, 5
Implementation steps:
---------------------
1. Make a sorted copy of the vector (descending)
2. Assign ranks to each unique value
3. Build a rank vector matching the original order
*/
vector<int> getRanks(const vector<int>& vec) {
// Step 1: Create a sorted copy (descending)
vector<int> sorted = vec;
std::sort(sorted.begin(), sorted.end(), std::greater<int>());
// Step 2: Map each unique value to its rank
std::map<int, int> rankMap; // value → rank
int rank = 1;
for (int value : sorted) {
// Assign rank only once per unique value
if (rankMap.find(value) == rankMap.end()) {
rankMap[value] = rank;
}
rank++; // next rank position
}
// Step 3: Build ranking vector in original order
vector<int> result;
result.reserve(vec.size());
for (int value : vec) {
result.push_back(rankMap[value]);
}
return result;
}
/*
FUNCTION: printRanking
-----------------------
Prints the original vector and its ranking.
*/
void printRanking(const vector<int>& vec, const vector<int>& ranks) {
std::cout << "Original vec: [ ";
for (int v : vec) std::cout << v << " ";
std::cout << "]\n";
std::cout << "Ranking vec : [ ";
for (int r : ranks) std::cout << r << " ";
std::cout << "]\n";
}
int main() {
vector<int> vec = {88, 4, 19, 4, 1, 31, 14, 1, 93, 17};
// Compute ranks
vector<int> rankingVec = getRanks(vec);
printRanking(vec, rankingVec);
}
/*
run:
Original vec: [ 88 4 19 4 1 31 14 1 93 17 ]
Ranking vec : [ 2 7 4 7 9 3 6 9 1 5 ]
*/
