hdoj 1176 免费馅饼

//转移方程:ans[t][x] = a[t][x] + max(ans[t - 1][x - 1], ans[t - 1][x], ans[t - 1][x + 1]) //关键处理开始的几秒 #include <iostream> #include <cstring> #include <algorithm> #include <string> #include <cstdio> using namespace std; int ans[100010][11]; int a[100010][11]; int n; int main() { //freopen("1.txt", "r", stdin); while(cin >> n && n != 0) { memset(a, 0, sizeof(a)); memset(ans, 0, sizeof(ans)); int t, x; int _maxT = 0; for(int i = 0; i < n; i++) { scanf("%d%d", &x, &t); a[t][x]++; _maxT = max(_maxT, t); } for(int i = 1; i <= _maxT; i++) { for(int j = 0; j <= 10; j++) { if(j == 0) ans[i][j] = max(ans[i - 1][j], ans[i - 1][j + 1]); else if(j == 10) ans[i][j] = max(ans[i - 1][j - 1], ans[i - 1][j]); else { ans[i][j] = max(ans[i - 1][j - 1], ans[i - 1][j]); ans[i][j] = max(ans[i][j], ans[i - 1][j + 1]); } ans[i][j] += a[i][j]; } if(i == 1) { ans[1][0] = 0; ans[1][1] = 0; ans[1][2] = 0; ans[1][3] = 0; ans[1][7] = 0; ans[1][8] = 0; ans[1][9] = 0; ans[1][10] = 0; } if(i == 2) { ans[1][0] = 0; ans[1][1] = 0; ans[1][2] = 0; ans[1][8] = 0; ans[1][9] = 0; ans[1][10] = 0; } if(i == 3) { ans[1][0] = 0; ans[1][1] = 0; ans[1][9] = 0; ans[1][10] = 0; } if(i == 4) { ans[1][0] = 0; ans[1][10] = 0; } } int _max = 0; for(int j = 0; j <= 10; j++) { if(ans[_maxT][j] > _max) _max = ans[_maxT][j]; } cout << _max << endl; } return 0; }