水题。
1 #include <cstdio> 2 #include <cstdlib> 3 #include <cstring> 4 5 #define MAXN 25 6 int dp[MAXN][MAXN*3]; 7 8 void init() { 9 int i, j, k; 10 11 memset(dp, 0, sizeof(dp)); 12 dp[0][0] = dp[1][1] = dp[1][2] = dp[1][3] = 1; 13 for (i=2; i<MAXN; ++i) { 14 for (j=0; j<MAXN*3; ++j) { 15 dp[i][j] += dp[i-1][j-1]; 16 if (j >= 2) 17 dp[i][j] += dp[i-1][j-2]; 18 if (j >= 3) 19 dp[i][j] += dp[i-1][j-3]; 20 } 21 } 22 } 23 24 int main() { 25 int a, b, t; 26 int i, j, k, tmp; 27 int mmin, mmax; 28 __int64 ans; 29 30 #ifndef ONLINE_JUDGE 31 freopen("data.in", "r", stdin); 32 #endif 33 34 init(); 35 36 while (scanf("%d %d %d", &a, &b, &t) != EOF) { 37 i = t / 15; 38 j = (i+1) / 2; 39 if (b < a) { 40 tmp = a - b; 41 mmin = j; 42 mmax = j * 3; 43 } else { 44 tmp = b - a; 45 mmin = tmp + i - j + 1; 46 mmax = j * 3; 47 } 48 ans = 0; 49 for (k=mmin; k<=mmax; ++k) 50 ans += dp[j][k]; 51 printf("%I64d ", ans); 52 } 53 54 return 0; 55 }