2 条题解
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0
by hansang:
#include <bits/stdc++.h> using namespace std; typedef long long LL; const int N=45; char s1[N], s2[N]; LL d[N], c[N][N], ans[N]; LL dfs(LL x, LL t, LL k){ if(t==0 && k==0) return 1; if(x<0 || t==0 || k<0) return 0; if(x & d[t-1]) return c[t-1][k] + dfs(x, t-1, k-1); else return dfs(x, t-1, k); } int main(){ d[0]=1; for(int i=1; i<=40; i++) d[i]=d[i-1]*2; memset(c, 0, sizeof(c)); c[0][0]=1; for(int i=1; i<=40; i++){ c[i][0]=1; for(int j=1; j<=i; j++) c[i][j]=c[i-1][j]+c[i-1][j-1]; } scanf("%s%s", s1+1, s2+1); LL K, A=0, B=0; scanf("%lld", &K); int len1=strlen(s1+1), len2=strlen(s2+1); for(int i=len1; i>=1; i--){ A+=(s1[len1-i+1]-'0')*d[i-1]; } for(int i=len2; i>=1; i--){ B+=(s2[len2-i+1]-'0')*d[i-1]; } if(A>B) swap(A, B); LL sum=0, t=0, k; for(int i=0; i<32; i++){ LL x=dfs(B, 32, i)-dfs(A-1, 32, i); if(sum+x<K) sum+=x, t=i; else {k=K-sum; break;} } t++; LL l=A, r=B, x=dfs(A-1, 32, t), res=0; while(l<=r){ LL mid=(l+r)/2; if(dfs(mid, 32, t)-x>=k) r=mid-1, res=mid; else l=mid+1; } int len=0; while(res>0) ans[++len]=res%2, res/=2; for(int i=len; i>=1; i--) printf("%d", ans[i]); printf("\n"); return 0; } -
0
huangzheng
LV 6
@ 2025-10-8 17:01:44
by hansang:
#include<bits/stdc++.h> using namespace std; typedef long long LL; const int N=45; char s1[N], s2[N]; LL d[N], c[N][N], ans[N]; LL dfs(LL x, LL t, LL k){ if(t0 && k0) return 1; if(x<0 || t==0 || k<0) return 0; if(x&d[t-1]) return c[t-1][k]+dfs(x, t-1, k-1); else return dfs(x, t-1, k); } int main(){ d[0]=1; for(int i=1; i<=40; i++) d[i]=d[i-1]*2; memset(c, 0, sizeof(c)); c[0][0]=1; for(int i=1; i<=40; i++){ c[i][0]=1; for(int j=1; j<=i; j++) c[i][j]=c[i-1][j]+c[i-1][j-1]; }scanf("%s%s", s1+1, s2+1); LL K, A=0, B=0; scanf("%lld", &K); int len1=strlen(s1+1), len2=strlen(s2+1); for(int i=len1; i>=1; i--){ A+=(s1[len1-i+1]-'0')*d[i-1]; } for(int i=len2; i>=1; i--){ B+=(s2[len2-i+1]-'0')*d[i-1]; } if(A>B) swap(A, B); LL sum=0, t=0, k; for(int i=0; i<32; i++){ LL x=dfs(B, 32, i)-dfs(A-1, 32, i); if(sum+x<K) sum+=x, t=i; else {k=K-sum; break;} } t++; LL l=A, r=B, x=dfs(A-1, 32, t), res=0; while(l<=r){ LL mid=(l+r)/2; if(dfs(mid, 32, t)-x>=k) r=mid-1, res=mid; else l=mid+1; } int len=0; while(res>0) ans[++len]=res%2, res/=2; for(int i=len; i>=1; i--) printf("%d", ans[i]); printf("\n"); return 0;}</pre>
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