Wrong allocation size lead to runtime error

[fbrunodr]

cpbook-code/ch9/SparseTable.cpp

Lines 17 to 22 in 26fb737

	P2.assign(L2_n, 0);
	L2.assign(1<<L2_n, 0);
	for (int i = 0; i <= L2_n; ++i) {
	P2[i] = (1<<i); // to speed up 2^i
	L2[(1<<i)] = i; // to speed up log_2(i)
	}

In line 17 we assign P2 a size of L2_n, implying we have the range [0,L2_n) available. Then we iterate i through [0,L2_n] and assign P2[i]. This leads to a problem when i = L2_n. This is a really hard to catch bug, as C++ usually allocate more size than necessary, but this very mistake has got me a runtime error in problem https://www.codechef.com/problems/TALCA?tab=statement

[wqweto]

Both P2 and L2 has to be bigger i.e. should be

    P2.assign(L2_n + 1, 0); 
    L2.assign((1<<L2_n) + 1, 0); 

These off-by-one errors both show up when _GLIBCXX_DEBUG is defined.