RMQ

 1 void RMQ(int num)
 2 {
 3     for(int j = 1; j < 20; ++j)
 4         for(int i = 1; i <= num; ++i)
 5             if(i + (1 << j) - 1 <= num)
 6             {
 7                 maxsum[i][j] = max(maxsum[i][j - 1], maxsum[i + (1 << (j - 1))][j - 1]);
 8                 minsum[i][j] = min(minsum[i][j - 1], minsum[i + (1 << (j - 1))][j - 1]);
 9             }
10 }
11 
12 int getmax(int l, int r) {
13     int k = (int)(log((r-l+1)*1.0) / log(2.0));
14     return max(maxsum[l][k], maxsum[r-(1<<k)+1][k]);
15 }
16 int getmin(int l, int r) {
17     int k = (int)(log((r-l+1)*1.0) / log(2.0));
18     return min(minsum[l][k], minsum[r-(1<<k)+1][k]);
19 }