【HDOJ】1166 敌兵布阵
线段树。
1 #include <stdio.h> 2 3 #define maxn 55555 4 5 int sums[maxn<<2]; 6 7 void PushUP(int rt) { 8 sums[rt] = sums[rt<<1] + sums[rt<<1|1]; 9 } 10 11 void build(int l, int r, int rt) { 12 int m; 13 if (l == r) { 14 scanf("%d", &sums[rt]); 15 return ; 16 } 17 m = (l+r)>>1; 18 build(l, m, rt<<1); 19 build(m+1, r, rt<<1|1); 20 PushUP(rt); 21 } 22 23 void update(int des, int delta, int l, int r, int rt) { 24 int m; 25 if (l == r) { 26 sums[rt] += delta; 27 return ; 28 } 29 m = (l+r)>>1; 30 if (des <= m) 31 update(des, delta, l, m, rt<<1); 32 else 33 update(des, delta, m+1, r, rt<<1|1); 34 PushUP(rt); 35 } 36 37 int query(int ll, int rr, int l, int r, int rt) { 38 int m, val = 0; 39 if (ll<=l && rr>=r) 40 return sums[rt]; 41 42 m = (l+r)>>1; 43 if (ll <= m) 44 val += query(ll, rr, l, m, rt<<1); 45 if (m < rr) 46 val += query(ll, rr, m+1, r, rt<<1|1); 47 48 return val; 49 } 50 51 int main() { 52 int case_n, n; 53 char cmd[10]; 54 int i, j, k; 55 56 scanf("%d", &case_n); 57 58 for (k=1; k<=case_n; ++k) { 59 scanf("%d", &n); 60 build(1, n, 1); 61 printf("Case %d:\n", k); 62 while (1) { 63 scanf("%*c%s", cmd); 64 if (cmd[0] == 'E') 65 break; 66 scanf("%d %d", &i, &j); 67 if (cmd[0] == 'Q') 68 printf("%d\n", query(i,j,1,n,1)); 69 else if (cmd[0] == 'A') 70 update(i, j, 1, n, 1); 71 else 72 update(i, -j, 1, n, 1); 73 } 74 } 75 76 return 0; 77 }
