/
another_knapsack.cpp
120 lines (107 loc) · 2.27 KB
/
another_knapsack.cpp
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#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define sf scanf
#define pf printf
long long int binarySearch(long long int arr[],long long int l, long long int r, long long int x)
{
while (l <= r)
{
long long int m = l + (r-l)/2;
if (arr[m] == x) return m; // Check if x is present at mid
if (arr[m] < x) l = m + 1; // If x greater, ignore left half
else r = m - 1; // If x is smaller, ignore left half
}
return -1; // if we reach here, then element was not present
}
void merge(long long int arr[], long long int l, long long int m, long long int r)
{
long long int i, j, k;
long long int n1 = m - l + 1;
long long int n2 = r - m;
/* create temp arrays */
long long int L[n1], R[n2];
/* Copy data to temp arrays L[] and R[] */
for(i = 0; i < n1; i++)
L[i] = arr[l + i];
for(j = 0; j < n2; j++)
R[j] = arr[m + 1+ j];
/* Merge the temp arrays back into arr[l..r]*/
i = 0;
j = 0;
k = l;
while (i < n1 && j < n2)
{
if (L[i] <= R[j])
{
arr[k] = L[i];
i++;
}
else
{
arr[k] = R[j];
j++;
}
k++;
}
/* Copy the remaining elements of L[], if there are any */
while (i < n1)
{
arr[k] = L[i];
i++;
k++;
}
/* Copy the remaining elements of R[], if there are any */
while (j < n2)
{
arr[k] = R[j];
j++;
k++;
}
}
/* l is for left index and r is right index of the sub-array
of arr to be sorted */
void mergeSort(long long int arr[], long long int l, long long int r)
{
if (l < r)
{
long long int m = l+(r-l)/2;//Same as (l+r)/2, but avoids overflow for large l and h
mergeSort(arr, l, m);
mergeSort(arr, m+1, r);
merge(arr, l, m, r);
}
}
void printArray(long long int A[], long long int size)
{
long long int i;
for (i=0; i < size; i++)
printf("%lld ", A[i]);
printf("\n");
}
int main()
{
ll n,m,i;
sf("%lld%lld",&n,&m);
ll x=(n*(n+1))/2;
ll c=0,n1=n,m1=m;
while(n1)
{
c++;
m1=m1-n1;
if(m1<0)
{
m1=m1+n1;
c--;
}
if(m1==0)
break;
n1--;
}
if(m<=n)
pf("1\n");
else if(m>x)
pf("-1\n");
else
pf("%lld\n",c);
return 0;
}