题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=3333
题意:求区间[l,r]内不重复的数字的和。
思路:存下所有的查询后排序,扫描原数组的时候记录当前数字的下标并且查看是否出现过,未出现过则更新a[i]到bit的[1,i]位置上;否则更新[上次位置,i]。一边更新一边查询,这样求和不会重复。
相当于一边更新一边查,把唯一的结果都尽可能地往右堆,因为保证了查询左边界一定是在移动的。
1 #include <algorithm> 2 #include <iostream> 3 #include <iomanip> 4 #include <cstring> 5 #include <climits> 6 #include <complex> 7 #include <fstream> 8 #include <cassert> 9 #include <cstdio> 10 #include <bitset> 11 #include <vector> 12 #include <deque> 13 #include <queue> 14 #include <stack> 15 #include <ctime> 16 #include <set> 17 #include <map> 18 #include <cmath> 19 using namespace std; 20 #define fr first 21 #define sc second 22 #define cl clear 23 #define BUG puts("here!!!") 24 #define W(a) while(a--) 25 #define pb(a) push_back(a) 26 #define Rint(a) scanf("%d", &a) 27 #define Rll(a) scanf("%I64d", &a) 28 #define Rs(a) scanf("%s", a) 29 #define Cin(a) cin >> a 30 #define FRead() freopen("in", "r", stdin) 31 #define FWrite() freopen("out", "w", stdout) 32 #define Rep(i, len) for(int i = 0; i < (len); i++) 33 #define For(i, a, len) for(int i = (a); i < (len); i++) 34 #define Cls(a) memset((a), 0, sizeof(a)) 35 #define Clr(a, x) memset((a), (x), sizeof(a)) 36 #define Full(a) memset((a), 0x7f7f7f, sizeof(a)) 37 #define lrt rt << 1 38 #define rrt rt << 1 | 1 39 #define pi 3.14159265359 40 #define RT return 41 #define lowbit(x) x & (-x) 42 #define onecnt(x) __builtin_popcount(x) 43 typedef long long LL; 44 typedef long double LD; 45 typedef unsigned long long ULL; 46 typedef pair<int, int> pii; 47 typedef pair<string, int> psi; 48 typedef pair<LL, LL> pll; 49 typedef map<string, int> msi; 50 typedef vector<int> vi; 51 typedef vector<LL> vl; 52 typedef vector<vl> vvl; 53 typedef vector<bool> vb; 54 55 typedef struct Query { 56 int l, r; 57 int id; 58 Query() {} 59 Query(int ll, int rr, int ii) : l(ll), r(rr), id(ii) {} 60 }Query; 61 const int maxn = 30100; 62 const int maxq = 100100; 63 int n, q, cur; 64 int a[maxn]; 65 LL bit[maxn]; 66 map<int, int> id; 67 68 Query query[maxq]; 69 LL ret[maxq]; 70 71 LL sum(int i) { 72 LL s = 0; 73 while(i > 0) { 74 s += bit[i]; 75 i -= lowbit(i); 76 } 77 return s; 78 } 79 80 void add(int i, int x) { 81 while(i <= n) { 82 bit[i] += x; 83 i += lowbit(i); 84 } 85 } 86 87 bool cmp(Query a, Query b) { 88 if(a.r == b.r) return a.l < b.l; 89 return a.r < b.r; 90 } 91 92 int main() { 93 // FRead(); 94 int T, l, r; 95 Rint(T); 96 W(T) { 97 Cls(bit); id.clear(); cur = 0; 98 Rint(n); 99 For(i, 1, n+1) Rint(a[i]); 100 Rint(q); 101 Rep(i, q) { 102 Rint(l); Rint(r); 103 query[i] = Query(l, r, i); 104 } 105 sort(query, query+q, cmp); 106 For(i, 1, n+1) { 107 if(id.find(a[i]) == id.end()) { 108 add(i, a[i]); 109 id[a[i]] = i; 110 } 111 else { 112 add(i, a[i]); 113 add(id[a[i]], -a[i]); 114 id[a[i]] = i; 115 } 116 while(query[cur].r == i) { 117 ret[query[cur].id] = sum(query[cur].r) - sum(query[cur].l-1); 118 cur++; 119 } 120 } 121 Rep(i, q) printf("%I64d ", ret[i]); 122 } 123 RT 0; 124 }