BZOJ1898: [Zjoi2005]Swamp 沼泽鳄鱼(矩阵快速幂)

题意

题目链接

sol

不难发现吃人鱼的运动每\(12s\)一个周期

所以暴力建12个矩阵，放在一起快速幂即可

最后余下的部分暴力乘

#include<bits/stdc++.h>
using namespace std;
const int maxn = 52, mod = 10000;
inline int read() {
    char c = getchar(); int x = 0, f = 1;
    while(c < '0' || c > '9') {if(c == '-') f = -1; c = getchar();}
    while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
    return x * f;
}
int n, m, s, t, k, mp[maxn][maxn], pos[maxn];
int add(int x, int y) {
    if(x + y < 0) return x + y + mod;
    return x + y >= mod ? x + y - mod : x + y;
}
int add2(int &x, int y) {
    if(x + y < 0) x = x + y + mod;
    else x = (x + y >= mod ? x + y - mod : x + y);
}
int mul(int x, int y) {
    return 1ll * x * y % mod;
}
struct ma {
    int m[maxn][maxn];
    ma() {
        memset(m, 0, sizeof(m));
    }
    ma operator * (const ma &rhs) const {
        ma ans;
        for(int k = 1; k <= n; k++)
            for(int i = 1; i <= n; i++)
                for(int j = 1; j <= n; j++) 
                    add2(ans.m[i][j], mul(m[i][k], rhs.m[k][j]));
        return ans;
    }
}a[15], bg;
ma matrixfp(ma a, int p) {
    ma base;
    for(int i = 1; i <= n; i++) base.m[i][i] = 1;
    while(p) {
        if(p & 1) base = base * a;
        a = a * a; p >>= 1;
    }
    return base;
}
int main() {
    n = read(); m = read(); s = read() + 1; t = read() + 1; k = read();
    for(int i = 1; i <= m; i++) {int x = read() + 1, y = read() + 1; bg.m[x][y]++; bg.m[y][x]++;}
    int fn = read();
    for(int i = 1; i <= 12; i++) a[i] = bg;
    for(int i = 1; i <= fn; i++) {
        int num = read();
        for(int j = 1; j <= num; j++) pos[j] = read() + 1;
        for(int j = 1; j <= 12; j++)
            for(int k = 1; k <= n; k++)
                a[j].m[k][pos[j % num + 1]] = 0;
    }
    ma res = a[1];
    //for(int i = 1; i <= n; i++) res.m[i][i] = 1;
    for(int i = 2; i <= 12; i++) res = res * a[i];
    res = matrixfp(res, k / 12);
    for(int i = 1; i <= k % 12; i++) res = res * a[i];
    printf("%d\n", res.m[s][t]);
    return 0;
}
/*
6 8 1 5 333
0 2
2 1
1 0
0 5
5 1
1 4
4 3
3 5
3
3 0 5 1
2 1 2
4 1 2 3 4 
*/