http://codeforces.com/contest/1073
A. Diverse Substring
1 #include <bits/stdc++.h> 2 using namespace std; 3 #define ll long long 4 #define minv 1e-6 5 #define inf 1e9 6 #define pi 3.1415926536 7 #define nl 2.7182818284 8 const ll mod=1e9+7;//998244353 9 const int maxn=1e3+10; 10 11 char s[maxn]; 12 13 int main() 14 { 15 int n,i; 16 scanf("%d",&n); 17 scanf("%s",s); 18 for (i=0;i<=n-2;i++) 19 if (s[i]!=s[i+1]) 20 break; 21 if (i==n-1) 22 printf("NO"); 23 else 24 { 25 printf("YES "); 26 printf("%c%c",s[i],s[i+1]); 27 } 28 return 0; 29 }
B. Vasya and Books
1 #include <iostream> 2 #include <cstdio> 3 using namespace std; 4 const int maxn=2e5+10; 5 6 int f[maxn]; 7 8 int main() 9 { 10 int n,a,v=0,i; 11 scanf("%d",&n); 12 for (i=1;i<=n;i++) 13 { 14 scanf("%d",&a); 15 f[a]=i; 16 } 17 for (i=1;i<=n;i++) 18 { 19 scanf("%d",&a); 20 if (i!=1) 21 printf(" "); 22 if (f[a]<v) 23 printf("0"); 24 else 25 printf("%d",f[a]-v); 26 v=max(f[a],v); 27 } 28 return 0; 29 }
C. Vasya and Robot
奇偶，负数取模
1 #include <bits/stdc++.h> 2 using namespace std; 3 #define ll long long 4 const int maxn=2e5+10; 5 const ll inf=1e9; 6 7 int px[maxn],py[maxn]; 8 9 int main() 10 { 11 char c; 12 int n,x,y,ax,ay,i,l,r,m,re; 13 scanf("%d ",&n); 14 for (i=1;i<=n;i++) 15 { 16 scanf("%c",&c); 17 if (c=='U') 18 x=0,y=1; 19 else if (c=='D') 20 x=0,y=-1; 21 else if (c=='L') 22 x=-1,y=0; 23 else 24 x=1,y=0; 25 px[i]=px[i-1]+x; 26 py[i]=py[i-1]+y; 27 } 28 scanf("%d%d",&ax,&ay); 29 if (px[n]==ax && py[n]==ay) 30 { 31 printf("0"); 32 return 0; 33 } 34 if (abs(ax+ay+n)%2==1) 35 { 36 printf("-1"); 37 return 0; 38 } 39 re=inf; 40 for (i=1;i<=n;i++) 41 { 42 l=i; 43 r=n; 44 while (l<=r) 45 { 46 m=(l+r)>>1; 47 ///change [i,m] ; use [1,i-1] [m+1,n] 48 if (m-i+1>=abs(px[i-1]+px[n]-px[m]-ax)+abs(py[i-1]+py[n]-py[m]-ay)) 49 r=m-1; 50 else 51 l=m+1; 52 } 53 if (l!=n+1) 54 re=min(re,l-i+1); 55 } 56 if (re==inf) 57 re=-1; 58 printf("%d",re); 59 return 0; 60 }
D. Berland Fair
1 #include <bits/stdc++.h> 2 using namespace std; 3 #define ll long long 4 const int maxn=2e5+10; 5 6 int nex[maxn],a[maxn]; 7 8 int main() 9 { 10 int n,i,j,g; 11 ll m,tot=0,num=0; 12 scanf("%d%lld",&n,&m); 13 14 for (i=0;i<n;i++) 15 scanf("%d",&a[i]),tot+=a[i]; 16 for (i=0;i<n;i++) 17 nex[i]=(i+1)%n; 18 g=n; 19 i=0; 20 j=n-1; 21 while (nex[i]!=i) 22 { 23 num+=m/tot*g; 24 m%=tot; 25 while (nex[i]!=i) 26 { 27 if (a[i]<=m) 28 { 29 m-=a[i]; 30 num++; 31 j=i; 32 } 33 else 34 { 35 nex[j]=nex[i]; 36 tot-=a[i]; 37 g--; 38 } 39 i=nex[i]; 40 if (m>=tot) 41 break; 42 } 43 } 44 num+=m/a[i]; 45 cout<<num; 46 return 0; 47 } 48 /* 49 1 100 50 1 51 52 3 1000 53 1 2 100 54 */
E. Segment Sum
代码是错的，以待后续埋坑
1 #include <bits/stdc++.h> 2 using namespace std; 3 #define ll long long 4 const ll mod=998244353; 5 const double minv=1e-10; 6 7 ll sum=0,shi[20],k,f[20][20]; 8 9 void work(ll a,int w,int g,int hav,ll num,int ori,int cond) 10 { 11 int s,gg,i,j,c; 12 if (a==0) 13 return; 14 s=a/shi[w]; 15 for (i=0;i<=s;i++) 16 { 17 gg=g-(!((hav>>i) & 1) && (!(i==0 && ori==1))); 18 if (gg>=0) 19 { 20 if (i<s) 21 { 22 /** 23 这一位选的是i， 24 除去这一位，还有w位， 25 从gg个数中选j个数作为需要添加的数(之前没出现过的)， 26 每一位都有k-gg+j种选择 27 **/ 28 f[0][0]=1; 29 for (j=1;j<=w;j++) 30 { 31 f[j][0]=f[j-1][0]*(k-gg)%mod; 32 ///already k-gg numbers 33 sum=(sum+f[j-1][0]* sum of k-gg numbers )%mod; 34 35 36 for (c=1;c<=min(gg,j);c++) 37 38 sum=(sum+f[j-1][c]* k-gg+c numbers + f[j-1][c-1]* any number(random average of gg numbers)) 39 40 41 f[j][c]=(f[j-1][c]*(k-gg+c)+f[j-1][c-1]*(10-(k-gg+c-1)))%mod; 42 } 43 for (c=0;c<=min(gg,w);c++) 44 sum=(sum+f[w][c]*cond)%mod; 45 46 47 ///geshu 48 // f[0][0]=1; 49 // for (j=1;j<=w;j++) 50 // { 51 // f[j][0]=f[j-1][0]*(k-gg)%mod; 52 // for (c=1;c<=min(gg,j);c++) 53 // f[j][c]=(f[j-1][c]*(k-gg+c)+f[j-1][c-1]*(10-(k-gg+c-1)))%mod; 54 // } 55 // for (c=0;c<=min(gg,w);c++) 56 // sum=(sum+f[w][c]*cond)%mod; 57 } 58 else 59 work(a%shi[w],w-1,gg,hav|(1<<i),ori&(i==0),cond); 60 } 61 } 62 } 63 64 int main() 65 { 66 ll l,r; 67 int i,w; 68 scanf("%lld%lld%d",&l,&r,&k); 69 shi[0]=1; 70 for (i=1;i<=18;i++) 71 shi[i]=shi[i-1]*10; 72 73 w=log(r+minv)/log(10); 74 work(r,w,k,0,0,1,1); 75 if (l!=1) 76 { 77 w=log(l-1+minv)/log(10);///l=1??? 78 work(l-1,w,k,0,0,1,-1); 79 } 80 printf("%lld",(sum+mod)%mod); 81 return 0; 82 }