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Cod sursa(job #941858)
#include <iostream>
#include <fstream>
using namespace std;
ifstream in ("rmq.in");
ofstream out ("rmq.out");
const int MAXN = 100010;
int N;
int V[MAXN], RMQ[18][MAXN];
int Log[MAXN];
void Build_Log ()
{
int i;
for (i = 2; i <= N; i ++)
Log[i] = Log[i / 2] + 1;
}
void Build_RMQ ()
{
int i, j, a, b;
for (i = 1; i <= N; i ++)
RMQ[0][i] = i;
for (j = 1; (1 << j) <= N; j ++)
for (i = 1; i + (1 << j) - 1 <= N; i ++){
a = RMQ[j - 1][i];
b = RMQ[j - 1][i + (1 << (j - 1))];
if (V[a] <= V[b])
RMQ[j][i] = a;
else
RMQ[j][i] = b;
}
}
int Solve (int x, int y)
{
if (y < x)
swap (x, y);
int dif = y - x + 1;
int log = Log[dif];
int a, b;
a = RMQ[log][x];
b = RMQ[log][y - (1 << log) + 1];
if (V[a] <= V[b])
return a;
else
return b;
}
int main()
{
int M, i, x, y;
in >> N >> M;
for (i = 1; i <= N; i ++)
in >> V[i];
Build_Log ();
Build_RMQ ();
while (M --){
in >> x >> y;
out << V[Solve (x, y)] << "\n";
}
return 0;
}