线段树区间增加/赋值 求区间和最大值最小值

/*
maxnode为区间长度的三倍
调用：
tree.update(1, 1, n);
tree.query(1, 1, n, 0);
n为区间长度,[y11, y22]为维护或查询区间,v为增加值或修改值
op == 1时区间加上v,op == 2时区间修改为v
*/
const int maxnode = 100000 * 3;
int _sum, _min, _max, op, y11, y22, v;
struct IntervalTree {
int sumv[maxnode], minv[maxnode], maxv[maxnode], setv[maxnode], addv[maxnode];

// 维护信息
void maintain(int o, int L, int R) {
int lc = o*2, rc = o*2+1;
if(R > L) {
sumv[o] = sumv[lc] + sumv[rc];
minv[o] = min(minv[lc], minv[rc]);
maxv[o] = max(maxv[lc], maxv[rc]);
}
if(setv[o] >= 0) { minv[o] = maxv[o] = setv[o]; sumv[o] = setv[o] * (R-L+1); }
if(addv[o]) { minv[o] += addv[o]; maxv[o] += addv[o]; sumv[o] += addv[o] * (R-L+1); }
}

// 标记传递
void unmark(int o) {
int lc = o*2, rc = o*2+1;
if(setv[o] >= 0) {
setv[lc] = setv[rc] = setv[o];
addv[lc] = addv[rc] = 0;
setv[o] = -1; // 清除本结点标记
}
if(addv[o]) {
addv[lc] += addv[o];
addv[rc] += addv[o];
addv[o] = 0; // 清除本结点标记
}
}

void update(int o, int L, int R) {
int lc = o*2, rc = o*2+1;
if(y11 <= L && y22 >= R) { // 标记修改
if(op == 1) addv[o] += v;
else { setv[o] = v; addv[o] = 0; }
} else {
unmark(o);
int M = L + (R-L)/2;
if(y11 <= M) update(lc, L, M); else maintain(lc, L, M);
if(y22 > M) update(rc, M+1, R); else maintain(rc, M+1, R);
}
maintain(o, L, R);
}

void query(int o, int L, int R, int add) {
if(setv[o] >= 0) {
int v = setv[o] + add + addv[o];
_sum += v * (min(R,y22)-max(L,y11)+1);
_min = min(_min, v);
_max = max(_max, v);
} else if(y11 <= L && y22 >= R) {
_sum += sumv[o] + add * (R-L+1);
_min = min(_min, minv[o] + add);
_max = max(_max, maxv[o] + add);
} else {
int M = L + (R-L)/2;
if(y11 <= M) query(o*2, L, M, add + addv[o]);
if(y22 > M) query(o*2+1, M+1, R, add + addv[o]);
}
}
} tree;