CF Educational Codeforces Round 50 (Rated for Div. 2) D. Vasya and Arrays ʕ •ᴥ•ʔ
D. Vasya and Arrays
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output
Vasya has two arrays A
and B of lengths n and m
, respectively.
He can perform the following operation arbitrary number of times (possibly zero): he takes some consecutive subsegment of the array and replaces it with a single element, equal to the sum of all elements on this subsegment. For example, from the array [1,10,100,1000,10000]
Vasya can obtain array [1,1110,10000], and from array [1,2,3] Vasya can obtain array [6]
.
Two arrays A
and B are considered equal if and only if they have the same length and for each valid i Ai=Bi
.
Vasya wants to perform some of these operations on array A
, some on array B, in such a way that arrays A and B
become equal. Moreover, the lengths of the resulting arrays should be maximal possible.
Help Vasya to determine the maximum length of the arrays that he can achieve or output that it is impossible to make arrays A
and B
equal.
Input
The first line contains a single integer n (1≤n≤3⋅105)
— the length of the first array.
The second line contains n
integers a1,a2,⋯,an (1≤ai≤109) — elements of the array A
.
The third line contains a single integer m (1≤m≤3⋅105)
— the length of the second array.
The fourth line contains m
integers b1,b2,⋯,bm (1≤bi≤109) - elements of the array B
.
Output
Print a single integer — the maximum length of the resulting arrays after some operations were performed on arrays A
and B
in such a way that they became equal.
If there is no way to make array equal, print "-1".
Examples
Input
Copy
5
11 2 3 5 7
4
11 7 3 7
Output
Copy
3
Input
Copy
2
1 2
1
100
Output
Copy
-1
Input
Copy
3
1 2 3
3
1 2 3
Output
Copy
3题意：给你两个字符串 问是否可以转换（相邻相加）成两个相同的字符串 如果不可以输出 -1 如果可以问最大长度是多少
#include
#include
#include
#include
#define ll long long
using namespace std;
int a[300010];
int b[300010];
int main()
{
int n,m;
scanf("%d",&n);
ll h1=0,h2=0;
int l=0;
for(int i=1;i<=n;i++)
scanf("%d",&a[i]),h1+=a[i];
scanf("%d",&m);
for(int i=1;i<=m;i++)
scanf("%d",&b[i]),h2+=b[i];
if(h1!=h2)
{
printf("-1\n");
return 0;
}
ll sa=0,sb=0;
int j=1;
for(int i=1;i<=n;i++)
{
sa+=a[i];
while(sa>sb)
{
sb+=b[j];
j++;
}
if(sa==sb)
l++;
}
printf("%d\n",l);
return 0;
}