LintCode Wood Cut

class Solution {
public:
/**
*@param L: Given n pieces of wood with length L[i]
*@param k: An integer
*return: The maximum length of the small pieces.
*/
int woodCut(vector<int> L, int k) {
// write your code here
long lo = 0;
long hi = 0;
for (int e : L) {
if (hi < e) {
hi = e;
}
}

hi++;
while (lo < hi) {
long mid = (lo + hi) / 2;
if (mid == 0) {
return 0;
}
long tryK = pieces(L, mid);
if (tryK >= k) {
lo = mid + 1;
} else {
hi = mid;
}
}

return lo - 1;
}

long pieces(vector<int>& L, long len) {
int count = 0;
for (int e : L) {
count += e / len;
}
return count;
}
};