lightoj 1032 - Fast Bit Calculations （数位DP）

/***********************************************
 * Author: fisty
 * Created Time: 2015-08-18 20:18:09
 * File Name   : 1032.cpp
 *********************************************** */
#include <iostream>
#include <cstring>
#include <deque>
#include <cmath>
#include <queue>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <string>
#include <vector>
#include <cstdio>
#include <bitset>
#include <algorithm>
using namespace std;
#define Debug(x) cout << #x << " " << x <<endl
#define Memset(x, a) memset(x, a, sizeof(x))
const int INF = 0x3f3f3f3f;
typedef long long LL;
typedef pair<int, int> P;
#define FOR(i, a, b) for(int i = a;i < b; i++)
#define lson l, m, k<<1
#define rson m+1, r, k<<1|1
#define MAX_N 32
int t;
int digit[MAX_N];
LL dp[MAX_N][MAX_N][2];
LL dfs(int len, int num, int e, int last){
    //当前在第len位， 前面有num个11，边界信息为e，最后一位为last
    if(len < 0) return num;
    if(!e && dp[len][num][last] != -1) return dp[len][num][last];

    LL ans = 0;
    int end = (e ? digit[len] : 1);
    for(int i = 0; i <= end; i++){
        if(i && last){
            //上一位和此位都为1
            ans += dfs(len-1, num+1, e&&i==end, i);
        }else{
            ans += dfs(len-1, num, e&&i==end, i);
        }
    }
    if(!e) dp[len][num][last] = ans;
    return ans;
}
LL solve(int n){
    int len = 0;
    Memset(dp, -1);
    while(n){
        digit[len++] = n % 2;
        n /= 2;
    }
    return dfs(len-1, 0, 1, 0);
}
int main() {
    //freopen("in.cpp", "r", stdin);
    //cin.tie(0);
    //ios::sync_with_stdio(false);
    scanf("%d", &t);
    int cnt = 1;
    while(t--){
        int n;
        scanf("%d", &n);
        printf("Case %d: %lld\n", cnt++, solve(n));
    }
    return 0;
}