UVA 1632 Alibaba——dp

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
const int maxn = 10005;
const int INF = 0x3f3f3f3f;
int n, a[maxn], b[maxn], dp[2][maxn][2];

int main() {
    while (~scanf("%d", &n)) {
        for (int i = 1; i <= n; i++) scanf("%d %d", &a[i], &b[i]);
        memset(dp, INF, sizeof(dp));
        for (int i = 1; i <= n; i++) dp[0][i][0] = dp[0][i][1] = 0;
        for (int i = 2; i <= n; i++) {
            for (int j = 1; j <= n - i + 1; j++) {
                dp[!(i&1)][j][0] = min(dp[!((i-1)&1)][j+1][0]+a[j+1]-a[j], dp[!((i-1)&1)][j+1][1]+a[j+i-1]-a[j]);
                dp[!(i&1)][j][1] = min(dp[!((i-1)&1)][j][0]+a[j+i-1]-a[j], dp[!((i-1)&1)][j][1]+a[j+i-1]-a[j+i-2]);
                if (dp[!(i&1)][j][0] >= b[j]) dp[!(i&1)][j][0] = INF;
                if (dp[!(i&1)][j][1] >= b[j+i-1]) dp[!(i&1)][j][1] = INF;
            }
        }
        int ans = min(dp[!(n&1)][1][0], dp[!(n&1)][1][1]);
        if (ans >= INF) printf("No solution\n");
        else printf("%d\n", ans);
    }
    return 0;
}
#include<iostream>  
#include<cstdio>  
#include<cstring>  
#include<cmath>  
#include<string>  
#include<queue>  
#include<cstdlib>  
#include<algorithm>  
#include<stack>  
#include<map>  
#include<queue>  
#include<vector>  
using namespace std;  
const int maxn = 1e4+10;  
const int INF = 0x3f3f3f3f;  
int p[maxn],t[maxn],dp[2][maxn][2],n,ans;  
int main(){  
 while(cin>>n){  
    for(int i=1;i<=n;i++) cin>>p[i]>>t[i];  
    for(int i=1;i<=n;i++) dp[0][i][0]=dp[0][i][1]=0;  
    int x,nx=0;  
    for(int i=1;i<n;i++){  
        x=nx;nx^=1;  
        for(int j=1;j<=n-i;j++){  
            //0->left 1->right  
  
            dp[nx][j][0]=min(dp[x][j+1][0]+p[j+1]-p[j],dp[x][j+1][1]+p[j+i]-p[j]);  
            dp[nx][j][1]=min(dp[x][j][0]+p[j+i]-p[j],dp[x][j][1]+p[i+j]-p[i+j-1]);  
            if(dp[nx][j][0]>=t[j]) dp[nx][j][0] = INF;  
            if(dp[nx][j][1]>=t[i+j]) dp[nx][j][1] = INF;  
        }  
    }  
    ans = min(dp[nx][1][0],dp[nx][1][1]);  
    if(ans>=INF) cout<<"No solution\n";  
    else cout<<ans<<"\n";  
  
 }  
    return 0;  
}