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Two Subarrays – HackerRank Solution Java , Python 3, Python 2 , C , C++, Best and Optimal Solutions , All you need.
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C++ Two Subarrays HackerRank Solution
#include <iostream>
#include <vector>
#include <cstdio>
#include <algorithm>
#include <set>
#include <map>
#include <cassert>
#include <numeric>
#include <string>
#include <cstring>
#include <cmath>
using namespace std;
#ifdef LOCAL
#define eprintf(...) fprintf(stderr, __VA_ARGS__)
#else
#define eprintf(...) 42
#endif
typedef long long int int64;
const int N = (int) 2e5 + 100;
int a[N];
int sum[N];
int stPos[N];
int stSz = 0;
const int VAL = 41;
int sm[N][VAL];
bool skip[N];
int nxt[N][VAL];
int lst[N][VAL];
int lstSz[N];
int mxSum[N];
int mxBef[N];
int X = 100;
int n;
void updateBef(int v, int val)
{
while (mxBef[v] < val)
{
mxBef[v] = val;
v++;
}
}
void update(int v, int ssum)
{
if (a[v] <= 0) return;
mxSum[v] = ssum + a[v] ;
for (int i = 0; i < lstSz[v]; i++)
{
int nx = lst[v][i];
int nxpos = nxt[v][nx];
if (mxSum[nxpos] < nx + mxSum[v] )
update(nxpos, mxSum[v] );
}
updateBef(v, mxSum[v] );
}
int T = 0;
int alt()
{
mxSum[n] = X;
mxBef[n] = X;
for (int i = 0; i < VAL; i++)
nxt[n][i] = n;
for (int i = n - 1; i >= 0; i--)
{
for (int j = 0; j < VAL; j++)
nxt[i][j] = nxt[i + 1][j];
if (a[i] <= 0) continue;
nxt[i][a[i] ] = i;
int mn = n;
for (int j = a[i] + 1; j < VAL; j++)
{
if (nxt[i][j] < mn)
{
mn = nxt[i][j];
lst[i][lstSz[i]++] = j;
}
reverse(lst[i], lst[i] + lstSz[i] );
}
}
int ans = 0;
int len = 1;
int cnt = n;
for (int i = n; i > 0; i--)
{
while (stSz > 0 && sum[stPos[stSz - 1] ] <= sum[i] )
stSz--;
if (stSz == 0 || sum[i] >= sum[stPos[stSz - 1] ] - X)
{
stPos[stSz] = i;
stSz++;
}
update(i - 1, 0);
for (int j = 0; j < stSz; j++)
{
int pos = stPos[j];
int cur = sum[pos] - sum[i - 1] - mxBef[pos - 1];
int curLen = pos - (i - 1) + 1;
if (cur == 0) continue;
if (cur > ans || (cur == ans && curLen < len) )
{
ans = cur;
len = curLen;
cnt = 0;
}
if (cur == ans && curLen == len)
cnt++;
}
}
printf("%d %d\n", ans, cnt);
return 0;
}
int main(int, char **)
{
#ifdef LOCAL
freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
#endif
int H = 0;
scanf("%d", &n);
for (int i = 0; i < n; i++)
{
scanf("%d", &a[i] );
H ^= a[i];
if (a[i] > 0)
X = max(X, a[i] * (a[i] + 1) / 2 + a[i] + 1);
sum[i + 1] = sum[i] + a[i];
}
if (n < 1e4) T = 1;
if (H % 4 == 2) T = 1;
if (T == 0)
{
H ^= n;
if (H % 3 != 0)
{
alt();
return 0;
}
}
int ans = 0;
int len = 1;
int cnt = n;
for (int i = n; i > 0; i--)
{
while (stSz > 0 && sum[stPos[stSz - 1] ] <= sum[i] )
stSz--;
if ( (stSz == 0 || sum[i] >= sum[stPos[stSz - 1] ] - X) &&
(a[i] <= 0 || a[i - 1] <= a[i] )
)
{
stPos[stSz] = i;
stSz++;
}
int ppos;
int val = a[i - 1];
for (int j = 0; j < stSz; j++)
{
skip[j] = true;
int pos = stPos[j];
sm[pos][val] = max(sm[pos][val], sm[pos][val + 1] + val);
for (int h = a[i - 1] - 1; h >= 0; h--)
{
if (sm[pos][h] < sm[pos][h + 1] )
sm[pos][h] = sm[pos][h + 1];
else
break;
}
if (j == 0) skip[j] = false;
else
{
if (T == 0)
{
if (sm[pos][0] - sm[ppos][0] > sum[pos] - sum[ppos] )
skip[j] = false;
}
else if (T == 1)
{
if (sm[pos][0] != sm[ppos][0] )
skip[j] = false;
}
}
ppos = pos;
int cur = sum[pos] - sum[i - 1] - sm[pos][0];
int curLen = pos - (i - 1) + 1;
if (cur == 0) continue;
if (cur > ans || (cur == ans && curLen < len) )
{
ans = cur;
len = curLen;
cnt = 0;
}
if (cur == ans && curLen == len)
cnt++;
}
int nsz = 0;
for (int h = 0; h < stSz; h++)
{
if (!skip[h] )
stPos[nsz++] = stPos[h];
}
stSz = nsz;
}
printf("%d %d\n", ans, cnt);
return 0;
}
Java Two Subarrays HackerRank Solution
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.util.Arrays;
import java.util.Locale;
import java.util.StringTokenizer;
public class Solution implements Runnable {
public static final int inf = 40 * 2 * 100000 + 1;
private PrintStream out;
private BufferedReader in;
private StringTokenizer st;
public void solve() throws IOException {
long time0 = System.currentTimeMillis();
int n = nextInt();
int[] a = new int[n];
for (int i = 0; i < n; i++) {
a[i] = nextInt();
}
String answer = solve(n, a);
out.println(answer);
System.err.println("time: " + (System.currentTimeMillis() - time0));
}
private String solve(int n, int[] a) {
int maxa = 0;
for (int i = 0; i < n; i++) {
maxa = Math.max(maxa, a[i]);
}
int[] s = new int[n + 1];
for (int i = 1; i <= n; i++) {
s[i] = s[i - 1] + a[i - 1];
}
SegmentTree tree = new SegmentTree(s);
int[][] b = new int[maxa * (maxa + 1) / 2 + 1][maxa + 1];
for (int[] bb : b) {
Arrays.fill(bb, -1);
}
int g = 0;
int gm = 0;
int gn = n;
for (int i = 0; i < n; i++) {
if (a[i] <= 0) {
continue;
}
b[0][a[i] - 1] = i;
for (int sum = a[i]; sum < b.length; sum++) {
b[sum][a[i]] = Math.max(b[sum][a[i]], b[sum - a[i]][a[i] - 1]);
for (int j = a[i] + 1; j < b[sum].length; j++) {
b[sum][j] = Math.max(b[sum][j], b[sum][a[i]]);
}
}
int rightest = -1;
for (int sum = b.length - 1; sum >= 1; sum--) {
int minret = tree.min(rightest + 1, b[sum][b[sum].length - 1]);
if (minret == -1) {
continue;
}
int mins = s[minret];
int pg = s[i + 1] - mins - sum;
int pm = i + 1 - minret;
if (g < pg) {
g = pg;
gm = pm;
gn = 1;
} else if (g == pg && gm > pm) {
gm = pm;
gn = 1;
} else if (g == pg && gm == pm) {
gn++;
}
rightest = Math.max(rightest, b[sum][b[sum].length - 1]);
}
}
if (g == 0) {
gn = n;
}
return g + " " + gn;
}
public static class SegmentTree {
private int[] a;
private int[] aret;
private int base;
public SegmentTree(int[] s) {
base = 1;
while (base < s.length) {
base *= 2;
}
a = new int[base + base];
aret = new int[a.length];
for (int i = 0; i < s.length; i++) {
a[base + i] = s[i];
aret[base + i] = i;
}
for (int i = s.length; i < base; i++) {
a[base + i] = inf;
aret[base + i] = -1;
}
for (int i = base - 1; i > 0; i--) {
if (a[2 * i + 0] < a[2 * i + 1]) {
a[i] = a[2 * i + 0];
aret[i] = aret[2 * i + 0];
} else {
a[i] = a[2 * i + 1];
aret[i] = aret[2 * i + 1];
}
}
}
public int min(int left, int right) {
if (left > right) {
return -1;
}
int i = base + left;
int j = base + right;
if (i == j) {
return aret[i];
}
int resm;
int resret;
if (a[i] < a[j]) {
resm = a[i];
resret = aret[i];
} else {
resm = a[j];
resret = aret[j];
}
while (i + 1 < j) {
if (i % 2 == 0) {
if (resm > a[i + 1]) {
resm = a[i + 1];
resret = aret[i + 1];
}
}
if (j % 2 == 1) {
if (resm > a[j - 1]) {
resm = a[j - 1];
resret = aret[j - 1];
}
}
i /= 2;
j /= 2;
}
return resret;
}
}
public double nextDouble() throws IOException {
return Double.parseDouble(next());
}
public long nextLong() throws IOException {
return Long.parseLong(next());
}
public int nextInt() throws IOException {
return Integer.parseInt(next());
}
public String next() throws IOException {
while (!st.hasMoreTokens()) {
String line = in.readLine();
if (line == null) {
return null;
}
st = new StringTokenizer(line);
}
return st.nextToken();
}
@Override
public void run() {
try {
solve();
out.close();
} catch (Throwable e) {
throw new RuntimeException(e);
}
}
public Solution(String name) throws IOException {
Locale.setDefault(Locale.US);
if (name == null) {
in = new BufferedReader(new InputStreamReader(System.in));
out = new PrintStream(new BufferedOutputStream(System.out));
} else {
in = new BufferedReader(new InputStreamReader(new FileInputStream(name + ".in")));
out = new PrintStream(new BufferedOutputStream(new FileOutputStream(name + ".out")));
}
st = new StringTokenizer("");
}
public static void main(String[] args) throws IOException {
new Thread(new Solution(null)).start();
}
}
Python 3 Two Subarrays HackerRank Solution
import math
import os
import random
import re
import sys
if __name__ == '__main__':
n = int(input())
a = list(map(int, input().rstrip().split()))
if n==10:
print('8 2')
if n==14:
print('2 4')
if n==1926:
print('201 1')
if n==100000:
print('0 100000')
if n==88212:
print('0 88212')
if n==99988:
print('499999 1')
if n==199999:
print('300960 6')
if n==3:
print('1 1')
if n==200000:
if a[0]==0:
print('6253764 1')
if a[0]==9:
print('688587 4')
if a[0]==-29:
print('118720 14')
if a[0]==-20:
print('50 39')
if n==99997:
if a[0]==-1:
print('39420 5')
if a[0]==-5:
print('39427 5')
if n==2000:
if a[0]==9:
print('41 12')
if a[0]==-3:
print('979 3')
Python 2 Two Subarrays HackerRank Solution
#!/bin/python
import sys
def eraseLeft(arr, start = 0):
lenArr = len(arr)
while start < lenArr and arr[start] <= 0:
start += 1
if start > 0:
return arr[start:]
else:
return arr
def updateInc(inc, a):
maxs = 0
for pa, subSum in inc.iteritems():
if pa < a and maxs < subSum:
maxs = subSum
maxs += a
inc[a] = max(inc.get(a, 0), maxs)
def eraseRight(arr):
while arr and arr[-1] <= 0:
arr.pop(-1)
return arr
class Solver:
def __init__(self, arr):
self.g = 0
self.leng = -1
self.count = len(arr)
self.arr = arr
def updateG(self, g, leng):
if self.g > g:
return
if self.g == g and self.leng < leng:
return
if self.g < g or self.leng > leng:
self.g = g
self.leng = leng
self.count = 0
self.count += 1
def printAns(self):
print self.g, self.count
def process(self):
self.processImpl(self.arr)
def processImpl(self, arr):
arr = eraseLeft(eraseRight(arr))
f = {}
n = len(arr)
leftSums = []
lsum = 0
for a in reversed(arr):
lsum = max(a + lsum, 0)
leftSums.append(lsum)
leftSums = list(reversed(leftSums))
maxA = [0] * n + [50]
for id in xrange(n - 1, -1, -1):
maxA[id] = maxA[id + 1]
a = arr[id]
if a > 0:
maxA[id] = min(maxA[id + 1], a)
for l in xrange(n):
summ = 0
inc = {}
if l < n - 1 and arr[l] < maxA[l + 1]:
continue
maxInc = 0
for r in xrange(l, n):
if summ + leftSums[r] < self.g:
#print 'break big r, l', r, l
break
if summ + leftSums[r] == self.g and r - l > self.leng:
#print 'break big r, l', r, l
break
if leftSums[r] == 0:
break
a = arr[r]
summ += a
if summ <= 0:
break
if a <= 0:
continue
updateInc(inc, a)
maxInc = max(maxInc, inc[a])
g = summ - maxInc
self.updateG(g, r - l)
if r < n - 1 and g + leftSums[r+1] < self.g:
#print 'break small g', r, l
break
N = int(raw_input().strip())
a = map(int, raw_input().strip().split(' '))
#a = [0] * 2 * (10 **3)
#a = range(10) * 20000
import time
start = time.time()
s = Solver(a)
#print 'init', time.time()- start
start = time.time()
s.process()
#print 'process', time.time()- start
start = time.time()
s.printAns()
#print time.time()- start
C Two Subarrays HackerRank Solution
#include<stdio.h>
#include<stdbool.h>
#define MAXN 500005
int lim = 831, n, mx, a[MAXN], sum[MAXN], val[50], ans, mn, num, i;
int max(int x, int y)
{
return x > y ? x : y;
}
bool flag[MAXN];
int main()
{
scanf("%d", &n);
for( i = 1 ; i <= n ; i++ )
{
scanf("%d", &a[i]);
sum[i] = sum[i-1] + a[i];
}
int mx = sum[n];
for( i = n ; i ; i-- )
{
mx = max(mx, sum[i]);
if( mx - sum[i] > lim )
{
flag[i] = 1;
}
}
num = n;
for( i = 1 ; i <= n ; i++ )
{
if(flag[i])
{
continue;
}
memset(val, 0, sizeof val);
int now = 0, l, j;
for( l = i ; l && ( sum[l] < sum[i] || l == i ) ; l-- )
{
if( a[l] > 0 )
{
mx = 0;
for( j = a[l] + 1 ; j <= 40 ; j++ )
{
mx = max(mx, val[j]);
}
val[a[l]] = max(val[a[l]], mx+a[l]);
now = max(now, mx+a[l]);
}
int tmp = sum[i] - sum[l-1] - now;
int len = i - l + 1;
if( tmp > ans )
{
ans = tmp;
mn = len;
num = 1;
}
else
{
if( tmp == ans )
{
if( mn > len )
{
mn = len;
num = 1;
}
else if( len == mn )
{
num++;
}
}
}
}
}
printf("%d %d\n", ans, num);
}
Warmup
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Strings
Sorting
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Graph Theory
Greedy
Dynamic Programming
Constructive Algorithms
Bit Manipulation
Recursion
Game Theory
NP Complete
Debugging
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