很明显 用线段树
节点类型 ：
typedef struct _NODE_
{
int L,R;
_NODE_* pLeft;
_NODE_* pRight;
LL nSum; // 原来的和
LL lnc; //增加量c的累加
}NODE;
感觉用孩子节点比较好一点 开到2n就行了
用2*n+1/2*n+2的话 要开到4n
http://poj.org/problem?id=3468
1 #include<iostream> 2 #include<cstdio> 3 using namespace std; 4 5 const int maxn = 200000 + 10; 6 typedef long long LL; 7 typedef struct _NODE_ 8 { 9 int L,R; 10 _NODE_* pLeft; 11 _NODE_* pRight; 12 LL nSum; 13 LL lnc; 14 }NODE; 15 16 NODE Tree[maxn]; 17 int nCount = 0; 18 int Mid(NODE* pRoot) 19 { 20 return (pRoot->L+pRoot->R)/2; 21 } 22 void BuildTree(NODE* pRoot,int L,int R) 23 { 24 pRoot->L = L; 25 pRoot->R = R; 26 pRoot->nSum = 0; 27 pRoot->lnc = 0; 28 if (L == R) 29 { 30 return ; 31 } 32 nCount++; 33 pRoot->pLeft = Tree + nCount; 34 nCount++; 35 pRoot->pRight = Tree + nCount; 36 BuildTree(pRoot->pLeft,L,(L+R)/2); 37 BuildTree(pRoot->pRight,(L+R)/2+1,R); 38 } 39 void Insert(NODE* pRoot,int i,int v) 40 { 41 if (pRoot->L==i&&pRoot->R==i) 42 { 43 pRoot->nSum = v; 44 return ; 45 } 46 pRoot->nSum+=v; 47 if (i<=Mid(pRoot)) 48 { 49 Insert(pRoot->pLeft,i,v); 50 } 51 else 52 { 53 Insert(pRoot->pRight,i,v); 54 } 55 } 56 57 void Add(NODE* pRoot,int a,int b,LL c) 58 { 59 if (pRoot->L==a&&pRoot->R==b) 60 { 61 pRoot->lnc+=c; 62 return ; 63 } 64 pRoot->nSum+=c*(b-a+1); 65 if (b<=(pRoot->L+pRoot->R)/2) 66 { 67 Add(pRoot->pLeft,a,b,c); 68 } 69 else if (a>=(pRoot->L+pRoot->R)/2+1) 70 { 71 Add(pRoot->pRight,a,b,c); 72 } 73 else 74 { 75 Add(pRoot->pLeft,a,(pRoot->L+pRoot->R)/2,c); 76 Add(pRoot->pRight,(pRoot->L+pRoot->R)/2+1,b,c); 77 } 78 } 79 80 LL QuerynSum(NODE* pRoot,int a,int b) 81 { 82 if (pRoot->L==a&&pRoot->R==b) 83 { 84 return pRoot->nSum+(pRoot->R-pRoot->L+1)*pRoot->lnc; 85 } 86 87 88 pRoot->nSum += (pRoot->R-pRoot->L+1)*pRoot->lnc; 89 Add(pRoot->pLeft,pRoot->L,Mid(pRoot),pRoot->lnc); 90 Add(pRoot->pRight,Mid(pRoot)+1,pRoot->R,pRoot->lnc); 91 pRoot->lnc = 0; 92 if (b<=Mid(pRoot)) 93 { 94 return QuerynSum(pRoot->pLeft,a,b); 95 } 96 else if (a>=Mid(pRoot)+1) 97 { 98 return QuerynSum(pRoot->pRight,a,b); 99 } 100 else 101 { 102 return QuerynSum(pRoot->pLeft,a,Mid(pRoot))+QuerynSum(pRoot->pRight,Mid(pRoot)+1,b); 103 } 104 105 } 106 107 108 void work() 109 { 110 int i,j,k; 111 int n,q; 112 scanf("%d%d",&n,&q); 113 int a,b,c; 114 nCount = 0; 115 char cmd[10]; 116 BuildTree(Tree,1,n); 117 for (i = 1;i<=n;i++) 118 { 119 scanf("%d",&a); 120 Insert(Tree,i,a); 121 } 122 for (i = 0;i<q;i++) 123 { 124 scanf("%s",cmd); 125 if (cmd[0]=='C') 126 { 127 scanf("%d%d%d",&a,&b,&c); 128 Add(Tree,a,b,c); 129 } 130 else 131 { 132 scanf("%d%d",&a,&b); 133 printf("%I64d ",QuerynSum(Tree,a,b)); 134 } 135 } 136 return ; 137 } 138 int main() 139 { 140 work(); 141 return 0; 142 }