hihoCoder#1077 RMQ问题再临-线段树

#include <iostream>
#include <climits>
using namespace std;

#define MAX_NODE 2000008

int N, Q;

struct SegmentTree {
int left[MAX_NODE];
int right[MAX_NODE];
int begin[MAX_NODE];
int end[MAX_NODE];
int value[MAX_NODE];
int root;
int size;

void init() {
size = 1;
left[0] = right[0] = root = 0;
value[0] = INT_MAX;
}

int insert(int v) {
value[size] = v;
size++;
return size - 1;
}

int _build(int l, int r) {
if (l > r)
return 0;
if (l == r) {
left[l] = right[l] = 0;
begin[l] = end[l] = l;
return l;
}

int lc = _build(l, (l + r) / 2);
int rc = _build((l + r) / 2 + 1, r);
int me = insert(-1);
left[me] = lc;
right[me] = rc;
begin[me] = l;
end[me] = r;
value[me] = min(value[lc], value[rc]);

return me;
}

void build() {
root = _build(1, size - 1);
}

int _query(int n, int l, int r) {
if (begin
== l && end
== r)
return value
;
int medium = (begin
+ end
) / 2;
if (r <= medium)
return _query(left
, l, r);
if (l > medium)
return _query(right
, l, r);
return min(_query(left
, l, medium), _query(right
, medium + 1, r));
}

int query(int l, int r) {
return _query(root, l, r);
}

void _update(int n, int p, int v) {
if (begin
== p && end
== p) {
value[p] = v;
return;
}
int medium = (begin
+ end
) / 2;
if (p <= medium)
_update(left
, p, v);
if (p > medium)
_update(right
, p, v);
value
= min(value[left
], value[right
]);
}

void update(int p, int v) {
_update(root, p, v);
}
} st;

int main() {
st.init();

scanf("%d", &N);
for (int i = 0; i < N; i++) {
int v;
scanf("%d", &v);
st.insert(v);
}

st.build();

scanf("%d", &Q);
while (Q--) {
int t, a, b;
scanf("%d%d%d", &t, &a, &b);
if (t)
st.update(a, b);
else
printf("%d\n", st.query(a, b));
}

return 0;
}