http://acm.sdut.edu.cn/bbs/read.php?tid=5651
。。本来只会向上更新 现在学习了如何向下更新 延迟标记法。。。使复杂度降低
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1 #include <iostream> 2 #include<cstdio> 3 #include<string.h> 4 using namespace std; 5 #define max 100000 6 __int64 s[max*4],te[max*4]; 7 void pushup(int w) 8 { 9 s[w] = s[2*w]+s[2*w+1]; 10 } 11 void pushdown(int w,int m) 12 { 13 if(te[w]) 14 { 15 te[2*w]+=te[w]; 16 te[2*w+1] += te[w]; 17 s[2*w] += (te[w]*(m-(m/2))); 18 s[2*w+1]+=(te[w]*(m/2)); 19 te[w] = 0;//将延迟标记去除 20 } 21 } 22 void build(int l,int r,int w) 23 { 24 te[w] = 0; 25 if(l==r) 26 { 27 scanf("%I64d",&s[w]); 28 return ; 29 } 30 int m = (l+r)/2; 31 build(l,m,2*w); 32 build(m+1,r,2*w+1); 33 pushup(w); 34 } 35 void add(int a,int b,int da,int l,int r,int w) 36 { 37 if(a<=l&&b>=r) 38 { 39 te[w] += da;//多次延迟标记 40 s[w]+=da*(r-l+1); 41 return ; 42 } 43 pushdown(w,r-l+1);//更新 44 int m = (l+r)/2; 45 if(a<=m) 46 add(a,b,da,l,m,2*w); 47 if(b>m) 48 add(a,b,da,m+1,r,2*w+1); 49 pushup(w); 50 } 51 __int64 search(int a,int b,int l,int r,int w) 52 { 53 if(a<=l&&b>=r) 54 { 55 return s[w]; 56 } 57 pushdown(w,r-l+1); 58 int m=(l+r)/2; 59 __int64 re = 0; 60 if(a<=m) 61 re+=search(a,b,l,m,2*w); 62 if(b>m) 63 re+=search(a,b,m+1,r,2*w+1); 64 return re; 65 } 66 int main() 67 { 68 int i,j,k,n,m,t,a,b,c; 69 char z; 70 scanf("%d%d",&n,&m); 71 build(1,n,1); 72 while(m--) 73 { 74 scanf("%*c%c",&z); 75 if(z=='Q') 76 { 77 scanf("%d%d",&a,&b); 78 printf("%I64d\n",search(a,b,1,n,1)); 79 } 80 else 81 { 82 scanf("%d%d%d",&a,&b,&c); 83 add(a,b,c,1,n,1); 84 } 85 } 86 return 0; 87 }