#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long LL;
const int N = 200010;
int n;
int a[N];
LL s[N];
int main()
{
cin >> n;
for(int i = 1; i <= n; i ++) cin >> a[i];
for(int i = 1; i <= n; i ++) s[i] = a[i] + s[i - 1];
LL res = 0;
for(int i = 1; i < n; i ++)
res += a[i] *(s[n] - s[i]);
cout << res << endl;
return 0;
}
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long LL;
const int N = 300010, M = N * 2;
int n;
int v[N];
int h[N], e[M], w[M], ne[M], idx;
LL f[N];
LL ans;
void add(int a, int b, int c)
{
e[idx] = b, w[idx] = c, ne[idx] = h[a], h[a] = idx ++ ;
}
void dfs(int u, int fa)
{
LL max1 = 0, max2 = 0;
for (int i = h[u]; ~i; i = ne[i])
{
int j = e[i];
if (j == fa) continue;
dfs(j, u);
if (f[j] - w[i] >= max1)
{
max2 = max1;
max1 = f[j] - w[i];
}
else if (f[j] - w[i] > max2)
{
max2 = f[j] - w[i];
}
}
ans = max(ans, v[u] + max1 + max2);
f[u] = v[u] + max1;
}
int main()
{
scanf("%d", &n);
memset(h, -1, sizeof h);
for (int i = 1; i <= n; i ++ ) scanf("%d", &v[i]);
for (int i = 0; i < n - 1; i ++ )
{
int a, b, c;
scanf("%d%d%d", &a, &b, &c);
add(a, b, c);
add(b, a, c);
}
dfs(1, -1);
printf("%lld\n", ans);
return 0;
}
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int val = -1, pos = -1;
for (int i = 1; i <= 100; i ++ ) {
int x = sc.nextInt();
if (x > val) {
val = x;
pos = i;
}
}
System.out.printf("%d\n%d\n", val, pos);
}
}
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 110;
int n;
int b[N];
int main()
{
cin >> n;
for (int i = 0; i < n; i ++ ) cin >> b[i];
int maxs = 0, mins = 0;
for (int i = 0; i < n; i ++ )
{
maxs += b[i];
if(!i || b[i] > b[i - 1])
mins += b[i];
}
cout << maxs << endl;
cout << mins << endl;
return 0;
}
/
#include<iostream>
#include<algorithm>
using namespace std;
const int N = 40;
int a[N], f[N];
int idx;
int main()
{
while(1)
{
int x;
cin >> x;
if(x == 0) break;
else a[idx ++] = x;
}
for(int i = 0; i < idx; i ++)
{
if(a[i] == 1) f[i] = 1;
if(a[i] == 2 && a[i - 1] != 2) f[i] = 2;
if(a[i] == 2 && a[i - 1] == 2) f[i] = f[i - 1] + 2;
}
int res = 0;
for(int i = 0; i < idx; i ++) res += f[i];
cout << res << endl;
return 0;
}
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
bool is_pri(int n)
{
if(n < 2) return 0;
for(int i = 2; i <= n / i; i ++)
{
if(n % i == 0)
return 0;
}
return 1;
}
int main()
{
int x;
cin >> x;
for(int i = 2; i <= x; i ++)
{
if(x % i != 0) continue;
int d = x / i;
if(is_pri(d) && is_pri(i))
{
cout << i << ' ' << d << endl;
break;
}
}
return 0;
}
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 200010;
bool yin[N];
int a[N];
int n;
int main()
{
cin >> n;
for(int i = 0; i < n; i ++)
{
int x;
cin >> x;
if(x >= 2 && x % 2 == 0) yin[i] = true;
x = x % 2;
a[i] = x;
}
bool res = true;
for(int i = 0; i < n; i ++)
{
if(a[i] == 1 && a[i + 1] == 1)
{
a[i] = 0;
a[i + 1] = 0;
continue;
}
if(a[i] == 1 && a[i + 1] == 0)
{
if(!yin[i + 1])
{
res = false;
break;
}
if(yin[i + 1])
{
if(a[i + 2] != 1 && !yin[i + 2])
{
res = false;
break;
}
}
if(yin[i + 1] && a[i + 2] == 1)
{
a[i] = 0;
a[i + 1] = 0;
a[i + 2] = 0;
}
if(yin[i + 1] && yin[i + 2])
{
a[i] = 0;
a[i + 1] = 0;
a[i + 2] = 1;
}
}
}
if(res) cout << "YES" << endl;
else puts("NO");
return 0;
}
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
int ans[4];
int main()
{
int n;
cin >> n;
int k = 0, i = -1;
while (n)
{
i ++ ;
k ++ ;
if (k % 7 == 0 || to_string(k).find('7') != -1) ans[i % 4] ++ ;
else n -- ;
}
for (int i = 0; i < 4; i ++ ) cout << ans[i] << endl;
return 0;
}
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 1010;
bool yin[N];
int a[N];
int t;
int main()
{
cin >> t;
int cnt = 1;
int summ = 0, res = 0, ress = 0;
while (t -- )
{
int m;
cin >> m;
for(int i = 1; i <= m; i ++) cin >> a[i];
int ans = a[1];
int c = 0;
bool st = false;
for(int i = 1; i <= m; i ++)
{
if(a[i] <= 0) ans += a[i];
if(a[i] > 0 && ans > a[i])
{
ans = a[i];
if(!st)
{
res ++;
yin[cnt] = true;
st = true;
}
}
}
summ += ans;
cnt ++;
}
cnt --;
for(int i = 2; i <= cnt + 1; i ++)
{
int a = i - 1, b = i + 1, c = i;
if(a > cnt) a -= cnt;
if(b > cnt) b -= cnt;
if(c > cnt) c -= cnt;
if(yin[a] && yin[b] && yin[c]) ress ++;
}
cout << summ << ' ' << res << ' ' << ress;
return 0;
}
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 1010;
bool yin[N];
int a[N];
int t;
int main()
{
cin >> t;
int cnt = 1;
int summ = 0, res = 0, ress = 0;
while (t -- )
{
int m;
cin >> m;
for(int i = 1; i <= m; i ++) cin >> a[i];
int ans = a[1];
int c = 0;
bool st = false;
for(int i = 1; i <= m; i ++)
{
if(a[i] <= 0) ans += a[i];
if(a[i] > 0 && ans > a[i])
{
ans = a[i];
if(!st)
{
res ++;
yin[cnt] = true;
st = true;
}
}
}
summ += ans;
cnt ++;
}
cnt --;
for(int i = 2; i <= cnt + 1; i ++)
{
int a = i - 1, b = i + 1, c = i;
if(a > cnt) a -= cnt;
if(b > cnt) b -= cnt;
if(c > cnt) c -= cnt;
if(yin[a] && yin[b] && yin[c]) ress ++;
}
cout << summ << ' ' << res << ' ' << ress;
return 0;
}
