C - The Battle of Chibi 树状数组+暴力DP
https://blog.csdn.net/loy_184548/article/details/50073559
1 #include <vector> 2 #include <map> 3 #include <set> 4 #include <algorithm> 5 #include <iostream> 6 #include <cstdio> 7 #include <cmath> 8 #include <cstdlib> 9 #include <string> 10 #include <cstring> 11 using namespace std; 12 #define MOD 1000000007 13 #define lowbit(x) ((x) & -(x)) 14 int num[1010]; 15 int dp[1010][1010]; 16 int b[1010]; 17 int n,m; 18 int sum(int x,int y) //计算y长度的子序列，前x项有多少种情况的和 19 { 20 int ret = 0; 21 while(x > 0) 22 { 23 ret = (ret + dp[x][y]) % MOD; 24 x -= lowbit(x); 25 } 26 return ret; 27 } 28 void add(int x,int y,int d) //更新x及以上长度，能取到的y的值为d 29 { 30 while(x <= n) 31 { 32 dp[x][y] = (dp[x][y] + d) % MOD; 33 x += lowbit(x); 34 } 35 } 36 int main(){ 37 int t; 38 scanf("%d",&t); 39 int cnt = 1; 40 while(t--) 41 { 42 43 scanf("%d%d",&n,&m); 44 memset(dp,0,sizeof(dp)); 45 for (int i = 1; i <= n; i++) 46 { 47 scanf("%d",&num[i]); 48 b[i] = num[i]; 49 } 50 sort(b + 1,b + 1 + n); 51 for (int i = 1; i<= n; i++) 52 { 53 num[i] = lower_bound(b + 1, b + 1 + n, num[i]) - b; //num[i]存储的是该位置是第几大的元素 54 } 55 for(int i=1;i<=n;i++) 56 printf("%d ",b[i]); 57 printf("\n"); 58 for(int i=1;i<=n;i++) 59 printf("%d ",num[i]); 60 printf("\n"); 61 for (int i = 1; i <= n; i++) 62 { 63 for (int j = 1; j <= min(i+1,m); j++) 64 { 65 if (j == 1) add(num[i],1,1); 66 else{ 67 int temp = sum(num[i] - 1,j - 1); 68 add(num[i],j,temp); 69 } 70 } 71 } 72 printf("Case #%d: %d\n",cnt++,sum(n,m)); 73 } 74 return 0; 75 }
