Kindergarten Adventures

                            Solution in C :

In  C++ :




#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef int _loop_int;
#define REP(i,n) for(_loop_int i=0;i<(_loop_int)(n);++i)
#define FOR(i,a,b) for(_loop_int i=(_loop_int)(a);i<(_loop_int)(b);++i)
#define FORR(i,a,b) for(_loop_int i=(_loop_int)(b)-1;i>=(_loop_int)(a);--i)

#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()

#define CHMIN(a,b) a=min((a),(b))
#define CHMAX(a,b) a=max((a),(b))

// mod
const ll MOD = 1000000007ll;
#define FIX(a) ((a)%MOD+MOD)%MOD

// floating
typedef double Real;
const Real EPS = 1e-11;
#define EQ0(x) (abs(x)<EPS)
#define EQ(a,b) (abs(a-b)<EPS)
typedef complex<Real> P;

int n;
int t[125252];
int imos[125252];

int main(){
  scanf("%d",&n);
  REP(i,n)scanf("%d",t+i);
  REP(i,n){
    int tt = t[i];
    int from = i+1;
    int to = (i-tt+n)%n;
    if(from<=to){
      imos[from]++;
      imos[to+1]--;
    }else{
      imos[0]++;
      imos[to+1]--;
      imos[from]++;
      imos[n]--;
    }
  }
  REP(i,n+1)imos[i+1]+=imos[i];
  int ans = -1;
  int val = -1;
  REP(i,n){
    if(imos[i]>val){
      ans = i;
      val = imos[i];
    }
  }
  printf("%d\n",ans+1);
  return 0;
}








In  Java :






import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int [] tab = new int[n];
        
        for(int i = 0; i < n; i++) {
            int k = sc.nextInt();
            
            if(k == 0) {
                continue;
            }
            
            tab[(i + 1) % n]++;
            int p = i - k + 1;
            if(p < 0) {
                p += n;
            }
            
            tab[p]--;
        }
        
        int max = -100000;
        int res = 0;
        int sum = 0;
        
        for(int i = 0; i < n; i++) {
            sum += tab[i];
            
            if(sum > max) {
                max = sum;
                res = i;
            }
        }
        
        System.out.println(res + 1);
    }
}








In C :




#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>

int main() {
    int n;
    scanf("%d", &n);
    int *dc = calloc(n, sizeof(int));
    int count = 0;
    for (int i = 0; i < n; i++) {
        int x;
        scanf("%d", &x);
        if (x < n) {
            int start = (i+1)%n;
            int end = (start-x+n)%n;
            dc[start]++;
            dc[end]--;
            if (end <= start) count++;
        }
    }
    int id = 0;
    int val = 0;
    for (int i = 0; i < n; i++) {
        count += dc[i];
        if (count > val) {
            val = count;
            id = i;
        }
    }
    printf("%d", id+1);
    free(dc);
    return 0;
}









In Python3 :






import sys
n = int(sys.stdin.readline())
t = [int(x) for x in sys.stdin.readline().split()]

current_available = 0
become_unavailable = [0] * (3 * n)
best_index = 1
best_result = 0
for i in range(2*n):
    el = t[i % n]
    become_unavailable[i + (n - el)] += 1
    if current_available > best_result:
        best_result = current_available
        best_index = i % n + 1
    if current_available == best_result:
        best_index = min(i % n + 1, best_index)
    current_available += 1
    current_available -= become_unavailable[i]
       
print(best_index)