Pagini recente » Cod sursa (job #2919697) | Cod sursa (job #1505299) | Cod sursa (job #1574729) | Cod sursa (job #2133178) | Cod sursa (job #1349437)
#include <iostream>
#include <fstream>
using namespace std;
const int maxn = 100005;
int n, m, aib[maxn];
inline int lsb(int x) {
return x & (-x);
}
inline void update(int node, int value) {
for(int i = node ; i <= n ; i += lsb(i))
aib[i] += value;
}
inline int query(int node) {
int sum = 0;
for(int i = node ; i > 0 ; i -= lsb(i))
sum += aib[i];
return sum;
}
inline int binarysearch(int x) {
int st = 1, dr = n, ans = -1;
while(st <= dr) {
int mid = ((st + dr) >> 1);
int q = query(mid);
if(q == x) {
ans = mid;
dr = mid - 1;
}
if(q > x)
dr = mid - 1;
else
st = mid + 1;
}
return ans;
}
int main() {
ifstream fin("aib.in");
ofstream fout("aib.out");
fin >> n >> m;
for(int i = 1 ; i <= n ; ++ i) {
int x;
fin >> x;
update(i, x);
}
for(int i = 1 ; i <= m ; ++ i) {
int op;
fin >> op;
++ op;
if(op == 1) {
int x, y;
fin >> x >> y;
update(x, y);
}
if(op == 2) {
int x, y;
fin >> x >> y;
fout << query(y) - query(x - 1) << '\n';
}
if(op == 3) {
int x;
fin >> x;
fout << binarysearch(x) << '\n';
}
}
}