5 6 1 2 3 4 5 Q 1 5 U 3 6 Q 3 4 Q 4 5 U 2 9 Q 1 5
5 6 59
#include <stdio.h> #include <string.h> #include <algorithm> using namespace std; int stu[200005]; struct Node { int l,r,maxn; } tree[1000000]; void Build(int t,int l,int r) { tree[t].l = l; tree[t].r = r; int mid = (l + r) / 2; if(l == r) { tree[t].maxn = stu[l]; return; } Build(2*t,l,mid); Build(2*t+1,mid+1,r); tree[t].maxn = max(tree[2*t].maxn,tree[2*t+1].maxn); } int Query(int t,int x,int y) { int l = tree[t].l; int r = tree[t].r; if(l == x && r == y) return tree[t].maxn; int mid = (l + r) / 2; if(x <= mid && y <= mid) return Query(2*t,x,y); else if(x > mid) return Query(2*t+1,x,y); else return max(Query(2*t,x,mid),Query(2*t+1,mid+1,y)); } void Modify(int t,int x,int der) { int l,r,mid; l = tree[t].l; r = tree[t].r; mid = (l + r) / 2; if(l == r) { tree[t].maxn = der; return; } if(x <= mid) Modify(2*t,x,der); else Modify(2*t+1,x,der); tree[t].maxn = max(Query(2*t,l,mid),Query(2*t+1,mid+1,r)); } int main() { int m,n,a,b; int i,j; char c[11]; while(scanf("%d%d",&n,&m) != EOF) { for(i = 1; i <= n; i++) { scanf("%d",&stu[i]); } Build(1,1,n); for(i = 0; i < m; i++) { scanf("%s%d%d",c,&a,&b); if(c[0] == 'Q') { if(a > b) { int tem = a; a = b; b = tem; } printf("%d\n",Query(1,a,b)); } else { Modify(1,a,b); } } } return 0; }