线段树之成段更新
成段更新就是在一个区域内进行操作，主要是要用lazy标记。
HDU - 1698
1 #include <iostream> 2 #include <stdio.h> 3 #include <string.h> 4 #define lson l,m,rt<<1 5 #define rson m+1,r,rt<<1|1 6 const int MAX = 1e5+10; 7 int tree[MAX<<2], col[MAX<<2]; 8 void PushUp(int rt){ 9 tree[rt] = tree[rt<<1] + tree[rt<<1|1]; 10 } 11 void PushDown(int rt, int m){ 12 if(col[rt]){ 13 col[rt<<1] = col[rt<<1|1] = col[rt]; 14 tree[rt<<1] = (m-(m>>1))*col[rt]; 15 tree[rt<<1|1] = (m>>1) * col[rt]; 16 col[rt] = 0; 17 } 18 } 19 void build(int l, int r, int rt){ 20 col[rt] = 0; 21 tree[rt] = 1; 22 if(l == r) return; 23 int m = (l+r) >> 1; 24 build(lson); 25 build(rson); 26 PushUp(rt); 27 } 28 void update(int L, int R, int c, int l, int r, int rt){ 29 if(L <= l && r <= R){ 30 col[rt] = c; 31 tree[rt] = c*(r-l+1); 32 return; 33 } 34 PushDown(rt,r-l+1); 35 int m = (l+r)>>1; 36 if(L <= m) update(L,R,c,lson); 37 if(R > m) update(L,R,c,rson); 38 PushUp(rt); 39 } 40 int main(){ 41 int t,n,m; 42 scanf("%d",&t); 43 for(int i = 1; i <= t; i ++){ 44 scanf("%d %d",&n,&m); 45 build(1,n,1); 46 while(m--){ 47 int l,r,num; 48 scanf("%d %d %d",&l,&r,&num); 49 update(l,r,num,1,n,1); 50 } 51 printf("Case %d: The total value of the hook is %d.\n",i,tree[1]); 52 } 53 return 0; 54 }
POJ - 3468
1 #include <iostream> 2 #include <stdio.h> 3 #include <string.h> 4 #define ll long long 5 #define lson l,m,rt<<1 6 #define rson m+1,r,rt<<1|1 7 using namespace std; 8 const int MAX = 100010; 9 ll tree[MAX<<2], add[MAX<<2]; 10 void PushUp(int rt){ 11 tree[rt] = tree[rt<<1]+tree[rt<<1|1]; 12 } 13 void PushDown(int rt, int m){ 14 if(add[rt]){ 15 add[rt<<1] += add[rt]; 16 add[rt<<1|1] += add[rt]; 17 tree[rt<<1] += add[rt]*(m-(m>>1)); 18 tree[rt<<1|1] += add[rt]*(m>>1); 19 add[rt] = 0; 20 } 21 } 22 void build(int l, int r, int rt){ 23 add[rt] = 0; 24 if(l == r){ 25 scanf("%lld",&tree[rt]); 26 return; 27 } 28 int m = (l+r)>>1; 29 build(lson); 30 build(rson); 31 PushUp(rt); 32 } 33 void update(int LL, int RR, int num, int l, int r, int rt){ 34 if(LL <= l && r <= RR){ 35 add[rt] += num; 36 tree[rt] += (ll)num * (r-l+1); 37 return; 38 } 39 PushDown(rt,r-l+1); 40 int m = (l+r)>>1; 41 if(LL <= m)update(LL,RR,num,lson); 42 if(m < RR) update(LL,RR,num,rson); 43 PushUp(rt); 44 } 45 ll query(int LL, int RR, int l, int r, int rt){ 46 if(LL <= l && r <= RR){ 47 return tree[rt]; 48 } 49 PushDown(rt,r-l+1); 50 int m = (l+r)>>1; 51 ll res = 0; 52 if(LL <= m) res += query(LL,RR,lson); 53 if(m < RR) res += query(LL,RR,rson); 54 return res; 55 } 56 int main(){ 57 int n,q; 58 scanf("%d %d",&n,&q); 59 build(1,n,1); 60 while(q--){ 61 char ch[10]; 62 int l,r,num; 63 scanf("%s",ch); 64 if(ch[0] == 'Q'){ 65 scanf("%d %d",&l,&r); 66 printf("%lld\n",query(l,r,1,n,1)); 67 }else{ 68 scanf("%d %d %d",&l,&r,&num); 69 update(l,r,num,1,n,1); 70 } 71 } 72 return 0; 73 }
