97 条题解

  • 0
    @ 2006-08-23 11:16:35

    第一次做就AC了,真是没话可说了

  • 0
    @ 2006-07-24 14:54:05

    没见过矩阵乘法的可以看这个来自Flymouse网站的讲稿。

    http://218.92.164.86/chenl/upload/离散数学在信息学竞赛中的运用.ppt

  • 0
    @ 2006-02-24 22:22:40

    想都不用想……7777777^2明显超出longint

  • 0
    @ 2006-02-23 23:20:31

    矩阵乘法~~~~~

    第一次没交过,没看见hint......

  • 0
    @ 2006-02-23 22:12:18

    So没意思……我能一次AC的题目不多的说

  • 0
    @ 2006-02-22 17:29:59

    看看 黑客帝国 吧...

  • -1
    @ 2017-09-05 21:23:24

    怀念玩*魔兽*的那段日子。默默地打掉了这道题。其实就是斐波拉契数列的进阶版。
    没什么说的,注意**long long**
    魔兽https://baike.baidu.com/item/%E9%AD%94%E5%85%BD%E4%BA%89%E9%9C%B8/128844?fr=aladdin
    #include <iostream>
    #include <cstdlib>
    #include <cstdio>
    #include <algorithm>
    #include <cmath>
    using namespace std;
    const long long mod=7777777ll;
    int x,y;
    int f[20];
    int n,m,k;
    struct ju
    {
    long long map[105][105];
    }base,now,js;
    ju operator *(ju a,ju b)
    {
    ju c;
    for(int i=0;i<k;i++)
    for(int j=0;j<k;j++)
    {
    c.map[i][j]=0;
    for(int l=0;l<k;l++)
    c.map[i][j]=(c.map[i][j]+a.map[i][l]*b.map[l][j])%mod;
    }
    return c;
    }
    ju operator +(ju a,ju b)
    {
    ju c;
    for(int i=0;i<k;i++)
    for(int j=0;j<k;j++)
    c.map[i][j]=(a.map[i][j]+b.map[i][j])%mod;
    return c;
    }
    ju qmi(int b)
    {
    ju bb=base;
    ju aa=now;
    while(b)
    {
    if(b%2==1)
    aa=aa*bb;
    bb=bb*bb;
    b>>=1;
    }
    return aa;
    }
    int main()
    {
    scanf("%d %d",&k,&n);
    for(int i=0;i<k;i++)
    for(int j=0;j<k;j++)
    {
    if(j==0) base.map[i][j]=1ll;
    else if(i+1==j) base.map[i][j]=1ll;
    else base.map[i][j]=0ll;
    }
    for(int i=0;i<k;i++)
    for(int j=0;j<k;j++)
    {
    if(i==j) now.map[i][j]=1ll;
    else now.map[i][j]=0ll;
    }
    f[0]=1;
    for(int i=1;i<=k;i++)
    for(int j=1;j<=min(i,k);j++)
    f[i]+=f[i-j];
    if(n<=k)
    {
    cout<<f[n];
    return 0;
    }
    for(int i=1;i<=k;i++)
    js.map[0][i-1]=f[k-i+1]*1ll;
    js=js*qmi(n-k);
    cout<<js.map[0][0];
    return 0;
    }

  • -1
    @ 2016-09-10 23:57:57

    矩阵乘法
    结果错在了f[i] = f[i - k] + ... + f[i - 1]没考虑i-k小于0的情况......
    #include <cstdio>
    #include <cstdlib>
    #include <cstring>
    #define rep(i, x, y) for (long long i = x; i <= y; ++i)
    #define MOD (7777777)
    using namespace std;

    long long b[16][16], a[16][16], c[16][16], f[16];

    void run(long long p) {
    if (p == 1) {
    memcpy(a, b, sizeof (a));
    return;
    }
    if (p % 2 == 0) {
    run(p / 2);
    memset(c, 0, sizeof (c));
    rep(i, 1, 10) rep(k, 1, 10) rep(j, 1, 10) {
    c[i][j] += a[i][k] * a[k][j];
    c[i][j] %= MOD;
    }
    }
    else {
    run(p - 1);
    memset(c, 0, sizeof (c));
    rep(i, 1, 10) rep(k, 1, 10) rep(j, 1, 10) {
    c[i][j] += a[i][k] * b[k][j];
    c[i][j] %= MOD;
    }
    }
    memcpy(a, c, sizeof (a));
    }
    int main(int argc, const char *argv[]) {
    long long k, n;
    scanf("%lld%lld", &k, &n);
    f[0] = 1;
    rep(i, 1, 12) {
    rep(j, i - k, i - 1) {
    if (j < 0) continue;
    f[i] += f[j];
    f[i] %= MOD;
    }
    }
    if (n <= 12) {printf("%lld\n", f[n]); return 0;}
    rep(i, 1, k) b[1][i] = 1;
    rep(i, 1, 10) b[i + 1][i] = 1;
    run(n - 12);
    long long ans = 0;
    rep(i, 1, 12) {
    ans += a[1][i] * f[13 - i];
    ans %= MOD;
    }
    printf("%lld\n", ans);
    return 0;
    }

  • -1
    @ 2016-04-15 16:50:31

    明显的矩阵乘法
    数组要用long long
    #include<cstdio>
    long long f[11],g[11],s[11][11],t[11][11];int n,m;
    int main()
    {
    scanf("%d%d",&n,&m);
    if(m<=n)
    {
    f[0]=1;
    for(int i=1;i<=m;++i)
    for(int j=1;j<=i;++j)
    f[i]+=f[i-j];
    printf("%lld\n",f[m]);
    return 0;
    }
    m-=n;f[0]=1;
    for(int i=1;i<=n;++i)
    for(int j=1;j<=i;++j)
    f[i]+=f[i-j];
    for(int i=1;i<n;++i)
    s[i+1][i]=s[i][n]=1;
    s[n][n]=1;
    for(;m;m>>=1)
    {
    if(m&1)
    {
    for(int i=1;i<=n;++i)
    for(int j=1;j<=n;++j)
    g[i]=(g[i]+f[j]*s[j][i])%7777777;
    for(int i=1;i<=n;++i)
    f[i]=g[i],g[i]=0;
    }
    for(int i=1;i<=n;++i)
    for(int j=1;j<=n;++j)
    {
    long long &temp=t[i][j];
    for(int k=1;k<=n;++k)
    temp=(temp+s[i][k]*s[k][j])%7777777;
    }
    for(int i=1;i<=n;++i)
    for(int j=1;j<=n;++j)
    s[i][j]=t[i][j],t[i][j]=0;
    }
    printf("%lld\n",f[n]);
    return 0;
    }

  • -1
    @ 2015-11-19 22:11:50

    #include <iostream>
    #include <cstdio>
    #include <cstring>
    #include <cmath>
    #include <algorithm>
    #include <vector>
    #include <queue>
    using namespace std;
    const int N = 25;
    const int MOD = 7777777;
    typedef long long LL;
    int t,m,n,k;
    struct Mat
    {
    LL s[12][12];
    }a,b;
    Mat multiply(Mat x, Mat y)
    {
    Mat c;
    memset(c.s,0,sizeof(c.s));
    for(int i = 0;i < k; ++i)
    {
    for(int j = 0;j < k; ++j)
    {
    for(int z = 0; z < k; ++z)
    {
    c.s[i][j] += x.s[i][z] * y.s[z][j];
    c.s[i][j] %= MOD;
    }
    }
    }
    return c;
    }
    void init()
    {
    memset(a.s,0,sizeof(a.s));
    memset(b.s,0,sizeof(b.s));
    a.s[0][0] = 1;
    for(int i = 1; i < k; ++i)
    {
    a.s[i][i-1] = 1;
    a.s[0][i] = 1;
    }
    for(int i = 0; i < k;i++)
    b.s[i][0] = 1;
    }
    LL calc()
    {
    while(n)
    {
    if(n & 1)
    b = multiply(b,a);
    a = multiply(a,a);
    n >>= 1;
    }
    return b.s[0][0];
    }
    int main()
    {
    #ifdef CDZSC_OFFLINE
    freopen("in.txt","r",stdin);
    #endif //CDZSC_OFFLINE
    while(~scanf("%d%d",&k,&n))
    {
    init();
    LL ans = calc();
    printf("%lld\n",ans);
    }
    }

  • -1
    @ 2015-10-05 17:15:19

    有什么问题就去找黎明前的光

  • -1
    @ 2015-08-09 13:18:27

    #include<cstdio>
    #include<cstring>
    #define MAXN 15
    using namespace std;

    int n, k;

    struct Matrix{
    long long int m[MAXN][MAXN];

    }s, t;

    void init(){
    int sum = 1;
    for(int i=1; i<=k; i++){
    s.m[i][i+1] = 1;
    s.m[k][i] = 1;
    t.m[i][1] = sum;
    sum += t.m[i][1];
    }
    }

    void clear(Matrix &x){
    for(int i=1; i<=k; i++)
    for(int j=1; j<=k; j++)
    x.m[i][j] = 0;
    }

    Matrix cheng(Matrix a, Matrix b){
    Matrix c;
    clear(c);
    for(int i=1; i<=k; i++)
    for(int j=1; j<=k; j++)
    for(int u=1; u<=k; u++){
    c.m[i][j] += a.m[i][u] * b.m[u][j];
    c.m[i][j] %= 7777777;
    }
    return c;
    }

    Matrix build(int x){
    if(x == 1)
    return s;
    Matrix a, b;
    if(x&1){
    a = build(x >> 1);

    b = cheng(a, a);
    b = cheng(b, s);

    }
    else{
    a = build(x >> 1);
    b = cheng(a, a);
    }
    return b;
    }

    int main()
    {
    scanf("%d%d", &k, &n);
    init();
    if(n != k){
    Matrix ans = cheng( build(n - k), t);
    printf("%lld", ans.m[k][1]);
    }
    else
    printf("%lld", t.m[k][1]);
    return 0;
    }
    矩阵乘法,要注意顺序。

  • -1
    @ 2015-03-22 21:01:58

    0ms飘过
    编译成功

    测试数据 #0: Accepted, time = 0 ms, mem = 284 KiB, score = 10
    测试数据 #1: Accepted, time = 0 ms, mem = 280 KiB, score = 10
    测试数据 #2: Accepted, time = 0 ms, mem = 284 KiB, score = 10
    测试数据 #3: Accepted, time = 0 ms, mem = 280 KiB, score = 10
    测试数据 #4: Accepted, time = 0 ms, mem = 284 KiB, score = 10
    测试数据 #5: Accepted, time = 0 ms, mem = 284 KiB, score = 10
    测试数据 #6: Accepted, time = 0 ms, mem = 284 KiB, score = 10
    测试数据 #7: Accepted, time = 0 ms, mem = 284 KiB, score = 10
    测试数据 #8: Accepted, time = 0 ms, mem = 284 KiB, score = 10
    测试数据 #9: Accepted, time = 0 ms, mem = 284 KiB, score = 10
    Accepted, time = 0 ms, mem = 284 KiB, score = 100

  • -1
    @ 2013-02-16 10:18:48
  • -1
    @ 2012-09-14 20:43:58

    矩阵乘法~

    太经典了~

  • -1
    @ 2010-07-08 10:59:39

    水过

  • -1
    @ 2010-04-07 20:09:19

    编译通过...├ 测试数据 01:答案正确...ms├ 测试数据 02:答案正确...ms├ 测试数据 03:答案正确...ms├ 测试数据 04:答案正确...ms├ 测试数据 05:答案正确...ms├ 测试数据 06:答案正确...ms├ 测试数据 07:答案正确...ms├ 测试数据 08:答案正确...ms├ 测试数据 09:答案正确...ms├ 测试数据 10:答案正确...msAccepted 有效得分:100 有效耗时:0ms

    矩阵乘法优化递推式~~

    复杂度:O(logn)

信息

ID
1067
难度
6
分类
动态规划 | 线性代数 | 矩阵乘法 点击显示
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递交数
3080
已通过
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