本来就对N*log(N)算法不大会....然后各种跪了，求出最长不下降+最长不上升-最少相同元素。求相同元素，用二分求上界搞的。代码里4个二分....
1 #include <cstdio> 2 #include <cstring> 3 #include <iostream> 4 #include <cmath> 5 #include <algorithm> 6 using namespace std; 7 int d[200001]; 8 int dd[200001]; 9 int f[200001]; 10 int a[200001]; 11 int same[200001]; 12 int n; 13 int bin1(int size,int x) 14 { 15 int l = 0,r = size-1,mid; 16 while(l <= r) 17 { 18 mid = (l+r)/2; 19 if(x >= f[mid-1]&&x < f[mid]) 20 return mid; 21 else if(x < f[mid]) r = mid-1; 22 else l = mid + 1; 23 } 24 return mid; 25 } 26 int binx(int size,int x) 27 { 28 int str = 0,end = size-1,mid; 29 while(str < end) 30 { 31 mid = (str+end)/2; 32 if(f[mid] < x) 33 str = mid + 1; 34 else 35 end = mid; 36 } 37 return str; 38 } 39 void LIS1() 40 { 41 int i,j,size = 1,k; 42 f[0] = a[0];d[0] = 1; 43 same[0] = 1; 44 for(i = 1;i < n;i ++) 45 { 46 if(a[i] < f[0]) 47 { 48 j = 0; 49 k = 0; 50 } 51 else if(a[i] >= f[size-1]) 52 { 53 j = size ++; 54 k = binx(size,a[i]); 55 } 56 else 57 { 58 j = bin1(size,a[i]); 59 k = binx(size,a[i]); 60 } 61 f[j] = a[i];d[i] = j + 1; 62 same[i] = min(same[i],j-k+1); 63 } 64 } 65 int bin2(int size,int x) 66 { 67 int l = 0,r = size-1,mid; 68 while(l <= r) 69 { 70 mid = (l+r)/2; 71 if(x <= f[mid-1]&&x > f[mid]) 72 return mid; 73 else if(x > f[mid]) r = mid-1; 74 else l = mid + 1; 75 } 76 return mid; 77 } 78 int bins(int size,int x) 79 { 80 int str = 0,end = size-1,mid; 81 while(str < end) 82 { 83 mid = (str+end)/2; 84 if(f[mid] > x) 85 str = mid + 1; 86 else 87 end = mid; 88 } 89 return str; 90 } 91 void LIS2() 92 { 93 int i,j,size = 1,k; 94 f[0] = a[0];d[0] = 1; 95 same[0] = 1; 96 for(i = 1;i < n;i ++) 97 { 98 if(a[i] > f[0]) 99 { 100 j = 0; 101 k = 0; 102 } 103 else if(a[i] <= f[size-1]) 104 { 105 j = size ++; 106 k = bins(size,a[i]); 107 } 108 else 109 { 110 j = bin2(size,a[i]); 111 k = bins(size,a[i]); 112 } 113 f[j] = a[i];d[i] = j + 1; 114 same[i] = min(same[i],j - k + 1); 115 } 116 } 117 int main() 118 { 119 int t,i; 120 scanf("%d",&t); 121 while(t--) 122 { 123 scanf("%d",&n); 124 for(i = 0;i < n;i ++) 125 { 126 scanf("%d",&a[i]); 127 same[i] = 1000000; 128 } 129 for(i = 0;i < n/2;i ++) 130 swap(a[i],a[n-i-1]); 131 memset(d,0,sizeof(d)); 132 memset(f,0,sizeof(f)); 133 LIS1(); 134 for(i = 0;i < n;i ++) 135 { 136 dd[i] = d[i]; 137 } 138 memset(d,0,sizeof(d)); 139 memset(f,0,sizeof(f)); 140 LIS2(); 141 int maxz = 0; 142 /*for(i = 0;i < n;i ++) 143 { 144 printf("%d ",dd[i]); 145 } 146 printf(" "); 147 for(i = 0;i < n;i ++) 148 { 149 printf("%d ",d[i]); 150 } 151 printf(" "); 152 for(i = 0;i < n;i ++) 153 { 154 printf("%d ",same[i]); 155 } 156 printf(" "); 157 */ 158 for(i = 0;i < n;i ++) 159 maxz = max(maxz,dd[i]+d[i]-same[i]); 160 printf("%d ",maxz); 161 } 162 return 0; 163 }