判断i到j 是否k步可达。
#include <cstdio> #include <algorithm> #include <iostream> #include <string.h> typedef long long LL; using namespace std; int n; int x[100], y[100]; struct Matrix { int m[40][40]; }; Matrix Mul(Matrix a, Matrix b) { Matrix ans; for (int i = 0; i < n; i++){ for (int j = 0; j < n; j++){ ans.m[i][j] = 0; for (int k = 0; k < n; k++){ ans.m[i][j] |= a.m[i][k] * b.m[k][j]; } } } return ans; } Matrix quick(Matrix a, int b) { Matrix ans; for (int i = 0; i < n;i++) for (int j = 0; j < n; j++) ans.m[i][j] = (i == j); while (b){ if (b & 1) ans = Mul(ans, a); a = Mul(a, a); b >>= 1; } return ans; } Matrix init() { int a, b; Matrix ans; cin >> a >> b; n = a*b; for (int i = 0; i < n;i++) for (int j = 0; j < n; j++) ans.m[i][j] = 0; for (int i = 0; i < a; i++){ for (int j = 0; j < b; j++){ getchar(); scanf("((%d,%d),(%d,%d),(%d,%d),(%d,%d))", &x[0], &y[0], &x[1], &y[1], &x[2], &y[2], &x[3], &y[3]); if(i==a-1&&j==b-1)continue;//图中路径不能经过终点 int t = i*b + j; for (int k = 0; k < 4; k++){ x[k]--; y[k]--; int t1 = x[k] * b + y[k]; ans.m[t][t1] = 1; } } } return ans; } void gao(Matrix a, int b) { int flag = 0; int flag1 = 0; Matrix ans; ans = quick(a, b); if(!ans.m[0][n-1]){ printf("False "); return ; } for(int i = 1;i<n-1;i++) if(ans.m[0][i]){ printf("Maybe ");return ; } printf("True "); } int main() { int T; int q; int t; cin >> T; while (T--){ Matrix ans = init(); cin >> q; while(q--){ scanf("%d", &t); gao(ans, t); } cout<<endl; } return 0; }