题解

1323 条题解

  • 0
    @ 2016-09-19 13:02:06

    无聊写的A+B问题。。。。
    c++
    #include<iostream>
    #include<algorithm>
    #include<cstring>
    #include<cstdio>
    #define INF 0x7fffffff
    using namespace std;
    int a,b,cnt;
    int ans[10],h[10],head[10],father[10],bit[10],mp[3][3],w[3],c[3],f[3];
    struct data1{int to,next,v;}e[10];
    struct data2{int x,y,v;}ed[10];
    struct data3{int l,r,sum;}tr[10];
    void insert(int u,int v,int w)
    {
    cnt++;
    e[cnt].to=v;
    e[cnt].v=w;
    e[cnt].next=head[u];
    head[u]=cnt;
    }
    bool bfs()
    {
    int q[10],t=0,w=1,i,now;
    memset(h,-1,sizeof(h));
    q[0]=h[0]=0;
    while(t<w)
    {
    now=q[t];t++;
    i=head[now];
    while(i)
    {
    if(e[i].v&&h[e[i].to]==-1)
    {q[w++]=e[i].to;h[e[i].to]=h[now]+1;}
    i=e[i].next;
    }
    }
    if(h[3]==-1)return 0;
    return 1;
    }
    int dfs(int x,int f)
    {
    if(x==3)return f;
    int w,used=0,i=head[x];
    while(i)
    {
    if(e[i].v&&h[e[i].to]==h[x]+1)
    {
    w=f-used;
    w=dfs(e[i].to,min(e[i].v,w));
    e[i].v-=w;
    e[i^1].v+=w;
    used+=w;
    if(used==f)return f;
    }
    i=e[i].next;
    }
    if(!used)h[x]=-1;
    return used;
    }
    void dinic()
    {
    cnt=1;
    memset(head,0,sizeof(head));
    insert(0,1,a);insert(1,0,0);
    insert(1,3,INF);insert(3,1,0);
    insert(0,2,b);insert(2,0,0);
    insert(2,3,INF);insert(3,2,0);
    while(bfs()){ans[1]+=dfs(0,INF);}
    }
    void spfa()
    {
    cnt=0;
    memset(head,0,sizeof(head));
    insert(0,1,a);
    insert(1,2,b);
    int dis[3],q[10],t=0,w=1,i,now;
    bool inq[10];
    memset(dis,127/3,sizeof(dis));
    memset(inq,0,sizeof(inq));
    q[0]=dis[0]=0;inq[0]=1;
    while(t<w)
    {
    now=q[t];t++;
    i=head[now];
    while(i)
    {
    if(e[i].v+dis[now]<dis[e[i].to])
    {
    dis[e[i].to]=e[i].v+dis[now];
    if(!inq[e[i].to])
    {
    inq[e[i].to]=1;
    q[w++]=e[i].to;
    }
    }
    i=e[i].next;
    }
    inq[now]=0;
    }
    ans[2]=dis[2];
    }
    void floyd()
    {
    memset(mp,127/3,sizeof(mp));
    mp[1][2]=a;mp[2][3]=b;
    for(int k=1;k<=3;k++)
    for(int i=1;i<=3;i++)
    for(int j=1;j<=3;j++)
    mp[i][j]=min(mp[i][j],mp[i][k]+mp[k][j]);
    ans[3]=mp[1][3];
    }
    void seg_build(int k,int s,int t)
    {
    tr[k].l=s;tr[k].r=t;
    if(s==t)return;
    int mid=(s+t)>>1;
    seg_build(k<<1,s,mid);
    seg_build(k<<1|1,mid+1,t);
    tr[k].sum=tr[k<<1].sum+tr[k<<1|1].sum;
    }
    void seg_change(int k,int x,int y)
    {
    int l=tr[k].l,r=tr[k].r;
    tr[k].sum+=y;
    if(l==r)return;
    int mid=(l+r)>>1;
    if(y<=mid)seg_change(k<<1,x,y);
    else seg_change(k<<1|1,x,y);
    }
    int seg_ask(int k,int x,int y)
    {
    int l=tr[k].l,r=tr[k].r;
    if(x==l&&y==r)return tr[k].sum;
    int mid=(l+r)>>1;
    if(mid>=y)return seg_ask(k<<1,x,y);
    else if(mid<x)return seg_ask(k<<1|1,x,y);
    else return seg_ask(k<<1,x,mid)+seg_ask(k<<1|1,mid+1,y);
    }
    void segtree()
    {
    seg_build(1,1,2);
    seg_change(1,1,a);
    seg_change(1,1,b);
    ans[4]=seg_ask(1,1,2);
    }
    int lowbit(int x){return x&(-x);}
    int bit_ask(int x)
    {
    int s=0;
    while(x)
    {
    s+=bit[x];
    x-=lowbit(x);
    }
    return s;
    }
    void bit_change(int x,int y)
    {
    while(x<=2)
    {
    bit[x]+=y;
    x+=lowbit(x);
    }
    }
    void bitree()
    {
    bit_change(1,a);
    bit_change(2,b);
    ans[5]=bit_ask(2);
    }
    int find(int x){return x==find(x)?x:father[x]=find(father[x]);}
    bool cmp(data2 a,data2 b){return a.v<b.v;}
    void kruskal()
    {
    ed[1].x=0;ed[1].y=1;ed[1].v=a;
    ed[2].x=1;ed[2].y=2;ed[2].v=b;
    sort(ed+1,ed+3,cmp);
    for(int i=0;i<=2;i++)father[i]=i;
    for(int i=1;i<=2;i++)
    {
    int x=father[ed[i].x],y=father[ed[i].y];
    if(x!=y){father[x]=y;ans[6]+=ed[i].v;}
    }
    }
    void dp()
    {
    w[1]=w[2]=1;
    c[1]=a;c[2]=b;
    for(int i=1;i<=2;i++)
    for(int v=2;v>=w[i];v--)
    f[v]=max(f[v],f[v-w[i]]+c[i]);
    ans[7]=f[2];
    }
    int main()
    {
    scanf("%d%d",&a,&b);
    dinic();//cout<<ans[1]<<endl;
    spfa();//cout<<ans[2]<<endl;
    floyd();//cout<<ans[3]<<endl;
    segtree();//cout<<ans[4]<<endl;
    bitree();//cout<<ans[5]<<endl;
    kruskal();//cout<<ans[6]<<endl;
    dp();//cout<<ans[7]<<endl;
    for(int i=1;i<=7;i++)ans[0]+=ans[i];
    ans[0]/=7;
    printf("%d",ans[0]);
    return 0;
    }

    23333333333333333333333333333333333333333333333333333

    ---转自黄学长

  • 0
    @ 2016-09-17 11:51:34
    #include<cstdlib>
    #include<cstdio>
    int main(int a,int b,int k)
    {
        if (k) scanf("%d%d",&a,&b);
        printf("%d",b==0?a:main(a^b,(a&b)<<1,0));
        exit(0);
    }
    

    233333333333333333

  • 0
    @ 2016-09-16 21:03:13

    #include<stdio.h>
    int main(){
    int a,b;
    scanf("%d%d",&a,&b);
    printf("%d",a+b);
    return 0;
    }

  • 0
    @ 2016-09-14 20:45:22

    #include<bits/stdc++.h>
    int main(int a,int b,int s)
    {
    if (!s)
    {
    printf("%d",b==0?a:main(a^b,(a&b)<<1,0));
    exit(0);
    }
    scanf("%d%d",&a,&b);
    main(a,b,0);
    }
    23333333333333333

  • 0
    @ 2016-09-13 23:27:26

    #include <iostream>
    using namespace std;
    int main()
    {
    int a, b;
    cin >> a >> b;
    cout << a + b << endl;
    return 0;
    }

  • 0
    @ 2016-09-06 19:53:33

    #include<stdio.h>
    int main( )
    {
    int a,b,c;
    scanf("%d %d",&a,&b);
    printf("%d",a+b);
    return 0;
    }

  • 0
    @ 2016-09-06 19:50:39

    #include<stdio.h>
    int main( )
    {
    int a,b,c;
    scanf("%d %d",&a,&b);
    printf("%d",a+b);
    return 0;
    }

  • 0
    @ 2016-09-06 19:49:17

    #include<stdio.h>
    int main()
    {
    int a,b;
    scanf("%d%d",&a,&b);
    printf("%d",a/b);
    return 0;
    }

  • 0
    @ 2016-09-03 15:52:21
    #include <iostream>
    #define a using
    #define b namespace
    #define c std
    #define d ;
    #define e int
    #define f main
    #define g (
    #define h )
    #define i {
    #define j }
    #define k cin
    #define l >>
    #define m return
    #define n ,
    #define o cout
    #define p <<
    #define q endl
    #define r +
    #define s 0
    
    a b c d
    
    e f g h
    i
        e aaa n bbb d
        k l aaa l bbb d
        o p aaa r bbb p q d
        m s d
    j
    

    加强版

  • 0
    @ 2016-09-03 15:48:40
    #include <iostream>
    #define a using
    #define b namespace
    #define c std
    #define d ;
    #define e int
    #define f main
    #define g (
    #define h )
    #define i {
    #define j }
    #define k cin
    #define l >>
    #define m return
    #define n ,
    #define o cout
    #define p <<
    #define q endl
    #define r +
    #define s 0
    
    a b c d
    
    e f g h
    {
        e aaa n bbb d
        k l aaa l bbb d
        o p aaa r bbb p q d
        m s d
    }
    

    我居然笑了

  • 0
    @ 2016-09-01 21:13:52

    #include<cstdio>
    int plus(int a,int b)
    {
    return b==0?a:plus(a^b,(a&b)<<1);
    }
    int main()
    {
    int a,b;scanf("%d%d",&a,&b);
    printf("%d",plus(a,b));
    }
    位运算

  • 0
    @ 2016-09-01 21:00:55

    #include<cstdio>
    int plus(int a,int b)
    {
    if (b==0) return a;
    plus(a^b,(a&b)<<1);
    }
    int main()
    {
    int a,b;scanf("%d%d",&a,&b);
    printf("%d",plus(a,b));
    }
    23333

  • 0
    @ 2016-08-23 14:09:56

    我才是最Diao的

    program 呵呵;
    var a,b:longint;
    begin
      randomize;
      readln(a,b);
      a:=random(60000);
      writeln(a);
    end.
    
    • @ 2016-09-03 15:43:29

      a+b最大65534……

  • 0
    @ 2016-08-18 21:50:12

    var a,b:integer;
    begin
    read(a,b);
    write(a+b);
    end.

  • 0
    @ 2016-08-18 13:06:29

    #include <iostream>
    #include <algorithm>
    #include <stdio.h>
    #include <string.h>
    #include <stdlib.h>
    using namespace std;
    int a[1001][1001];
    int f[1001][1001];
    int max(int a, int b){
    return a > b ? a : b;
    }
    int main(){
    memset(a, 0, sizeof(a));
    memset(f, 0, sizeof(f));
    int i,j,k,n,m;
    scanf("%d%d", &n, &m);
    for(i = 1; i <= n; i++)
    for(j = 1; j <= m; j++) scanf("%d", &a[i][j]);
    for(i = 1; i <= n; i++){
    for(j = 1; j <= m; j++){
    int tmp = max(f[i - 1][j] + a[i][j], f[i][j - 1] + a[i][j]);
    f[i][j] = (f[i][j], tmp);
    }
    }
    printf("%d\n", f[n][m]);
    return 0;
    }

  • 0
    @ 2016-08-18 13:05:57

    #include <iostream>
    #include <algorithm>
    #include <stdio.h>
    #include <string.h>
    #include <stdlib.h>
    using namespace std;
    int a[100001];
    int f[100001];
    int max(int a, int b){
    return a > b ? a : b;
    }
    int pre[100001];
    int main(){
    memset(pre, 0, sizeof(pre));
    int i,j,k,n,m;
    int ans = 0;
    scanf("%d", &n);
    for(i = 1; i <= n; i++) scanf("%d", &a[i]);
    f[0] = 0; f[1] = 1; pre[1] = 1;
    for(i = 2; i <= n; i++){
    int MAXN = 0;
    ans = 0;
    for(j = 1; j <= i; j++){
    if(a[j] <= a[i] && f[j] > MAXN){MAXN = f[j]; ans = j;}
    }
    f[i] = max(MAXN + 1, 1);
    if(ans == 0) pre[i] = i;
    else pre[i] = ans;
    }
    printf("%d\n", f[n]);
    int MAXN = 0;
    for(i = n; i >= 1; i--){
    if(f[i] > MAXN){
    MAXN = f[i];
    ans = i;
    }
    }
    printf("%d ", a[ans]);
    for(i = ans; i != pre[i]; i = pre[i]){
    printf("%d ", a[pre[i]]);
    }
    //for(i = 1; i <= n; i++) cout<<i<<": "<<pre[i]<<endl;
    printf("\n");
    return 0;
    }
    /*
    6
    5 3 4 8 6 7
    */

  • 0
    @ 2016-08-18 13:05:21

    #include <iostream>
    #include <algorithm>
    #include <stdio.h>
    #include <string.h>
    #include <stdlib.h>
    #define MAXN 1e16
    using namespace std;
    long long f[10001];
    int a[10001];
    int main(){
    memset(f, 0, sizeof(f));
    freopen("rand.out", "r", stdin);
    freopen("硬币.out", "w", stdout);
    int i,j,k,n,m,x,y,z;
    scanf("%d", &m);
    for(i = 1; i <=m; i++) scanf("%d", &a[i]);
    scanf("%d", &n);
    f[0] = 0;
    for(i = 1; i <= n; i++){
    long long minn = MAXN;
    for(j = 1; j <= m && a[j] <= i; j++){
    //cout<<i<<": "<<f[i - a[j]]<<endl;
    if(f[i - a[j]] < minn && a[j] <= i){
    minn = f[i - a[j]] + 1;
    //cout<<i<<": "<<1<<endl;
    }
    }
    f[i] = minn;
    //else if(flag == 0)
    //cout<<i<<": "<<f[i]<<endl;
    }
    if(f[n] == MAXN) printf("Impossible\n");
    else printf("%lld\n", f[n]);
    return 0;
    }

  • 0
    @ 2016-08-14 12:04:16

    #include<stdio.h>
    int main()
    {
    int a,b;
    scanf("%d%d",&a,&b);
    printf("%d\n",a+b);
    }
    你们为什么这么diao

  • 0
    @ 2016-04-20 22:03:34
    #include <stdio.h>
    int main()
    {
        int a, b;
        scanf("%d%d", &a, &b);
        printf("%d\n", a + b);
        return 0;
    }
    
  • 0

    A+B问题,一道历史悠久的问题,下面就给出该题的多种解法。

    解法一:首先用cin/scanf读入两个int类型数a和b,再用cout/printf输出a+b的结果。核心代码:cin>>a>>b; cout<<a+b<<endl;

    解法二:为了防止计算a+b时占用过多内存(其实也没多少),可使用C++的提供的内联汇编来完成本题。核心代码:

    __asm
    (
    "mov %1,%%eax \n\t"
    "mov %2,%%ebx \n\t"
    "add %%eax,%%ebx \n\t"
    "mov %%ebx,%0"
    :"=m"(b)
    :"m"(a),"m"(b)
    );
    最后输出b即可。(事实上,这就是不让编译器替我们把高级语言翻译为汇编语言,直接就替它做了)

    解法三:为防止出题人故意出大数据恶心我们,可采用高精度加法完成此题。核心代码:

    char s1[101] , s2[101] , l1 , l2 , l3;
    int a[101]={0} , b[101]={0} , c[102]={0};
    cin >> s1 >> s2;
    l1 = strlen(s1);
    l2 = strlen(s2);
    for (int i = 0 ; i < l1 ; i++) a[l1 - i] = s1[i] - '0';
    for (int i = 0 ; i < l2 ; i++) b[l2 - i] = s2[i] - '0';
    l3 = max(l1 , l2);
    for (int i = 1 ; i <= l3 ; i++)
    {
    c[i] += a[i] + b[i];
    c[i + 1] = c[i] / 10;
    c[i] %= 10;
    }
    if (c[l3 + 1] == 1) l3++;
    for (int i = l3 ; i >= 1 ; i--) cout << c[i]; cout<<endl;

    解法四:(从此以后均为扯淡)

    设f[i][j]表示i+j的值。可得状态转移方程为f[i][j] = max(f[i-1][j]+1 , f[i][j-1]+1)。由于任何数加0数值不变(公理),所以边界条件为f[0][i]=f[i][0]=i。最后输出f[a][b]即可。核心代码:

    for (int i = 1 ; i <= a ; i++) f[i][0] = i;
    for (int i = 1 ; i <= b ; i++) f[0][i] = i;
    for (int i = 1 ; i <= a ; i++)
    for (int j = 1 ; j <= b ; j++)
    f[i][j] = max(f[i - 1][j] + 1 , f[i][j - 1] + 1);

    解法五:分析解法四时间复杂度知若时间为O(a*b)。若a*b过大则程序必定超时。观察代码容易发现,根据分配律(公理)得:

    f[i][j-1]+1=(i)+(j-1)+1=(i)+(j)-1+1=(i-1)+(j)+1=f[i-1][j]+1

    根据上式我们可以立即将时间和空间复杂度都降低一维。核心代码:

    f[0] = 0;
    for (int i = 1 ; i <= max(a , b) ; i++)
    f[i] = f[i - 1] + 1;

    最后输出f[a]+f[b]。可以看到,时间复杂度为O(max(a,b)),为线性,可以通过此题。

    解法六:

    首先orz给出本解法的神犇

    设图G=(V, E)为一流网络,包含2个源点S1、S2和1个汇点T。构造该图使得:

    从S1、S2分别发出a、b条边,每条边的容量为1,这些边应当连接到max(a, b)个顶点上,且没有两条边拥有相同的两个端点。从这max(a, b)个顶点分别连一条容量为+∞的边到汇点T。然后在这个流网络上面跑Dinic算法、Ford-Fulkerson算法之类的东西,可以练练写网络流的手感。

信息

ID
1000
难度
9
分类
(无)
标签
(无)
递交数
74446
已通过
28492
通过率
38%
被复制
223