This page allows you to generate online graphs or graph problems. It is a CGI interface that calls the Build Graph program of the B++ Library. The server where the program runs is a Pentium 200 MHz under Linux, so be patient with it and please do not call the program several times at the same moment. If we notice severe abuse on this server, we will shut down the facility. Thanks in advance for your comprehension, and do not forget that if you need to use intensively this program, its and for Windows are available.
Option +connex of the Build Graph program. Generates a graph with x nodes and y arcs. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is not used here.
Option +nonconnex of the Build Graph program. Generates a non necessarily connex graph with x nodes and y arcs. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is not used here.
Option +arcvalue of the Build Graph program. Generates a connex graph with x nodes and y arcs, each arc with a value between 0 and u. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is the value of the arc.
Option +serial of the Build Graph program. Generates a connex serialparallel graph with x nodes and y arcs. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is not used here.
Option +tree of the Build Graph program. Generates a tree with x nodes. The output format is defined as follows:
node #1 = #2
#1 is the number of the node,
#2 is not used here.
arc #1 = #2 , #3 ; #4
#1 is the number of the arc,
#2 is the source node number of the arc,
#3 is the target node number of the arc,
#4 is not used here.
Option +maxflow of the Build Graph program. Generates a maximum flow problem as a graph with x nodes and y arcs (without counting the unique source and target nodes, and their arcs), and a flow capacity scale of u for the arcs. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4 ; #5
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is the maximum capacity of the arc,
 #5 is not used here.
Option +minflow of the Build Graph program. Generates a minimum cost flow problem as a graph with x nodes and y arcs, an arccapacity scale of u, an arccapacity flexibility of v %. The cost functions of the arcs are defined by a value chosen between 0 and w. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4 , #5 ; #6 ; #7
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is the minimum capacity of the arc,
 #5 is the maximum capacity of the arc,
 #6 is the unit cost of the flow of the arc,
 #7 is not used here.
Option +mintension1 of the Build Graph program. Generates a minimum cost tension problem as a graph with x nodes and y arcs, a nodepotential scale of u, an arctension flexibility of v %. The cost functions of the arcs are defined by two values chosen between 0 and w. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4 , #5 , #6 ; #7 , #8 ; #9
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is the minimum tension of the arc,
 #5 is the maximum tension of the arc,
 #6 is the optimum tension of the arc (i.e. where the cost is zero),
 #7 is the unit cost of the tension of the arc when below the optimum,
 #8 is the unit cost of the tension of the arc when above the optimum,
 #9 is not used here.
Option +mintension1s of the Build Graph program. Generates a minimum cost tension problem as a serialparallel graph with x nodes and y+y' arcs (y for the serialparallel structure and y' for the disruption), a nodepotential scale of u, an arctension flexibility of v %. The cost functions of the arcs are defined by two values chosen between 0 and w. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4 , #5 , #6 ; #7 , #8 ; #9
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is the minimum tension of the arc,
 #5 is the maximum tension of the arc,
 #6 is the optimum tension of the arc (i.e. where the cost is zero),
 #7 is the unit cost of the tension of the arc when below the optimum,
 #8 is the unit cost of the tension of the arc when above the optimum,
 #9 is not used here.
Option +mintension5 of the Build Graph program. Generates a minimum cost tension problem as a graph with x nodes and y arcs, a nodepotential scale of u, a minimum cardinality of v for the feasible tension sets. The cost functions of the arcs are defined by two values chosen between 0 and w. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4  #4  ... , #5 ; #6 , #7 ; #8
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is a feasible tension of the arc,
 #5 is the optimum tension of the arc (i.e. where the cost is zero),
 #6 is the unit cost of the tension of the arc when below the optimum,
 #7 is the unit cost of the tension of the arc when above the optimum,
 #8 is not used here.
Option +mintension5s of the Build Graph program. Generates a minimum cost tension problem as a serialparallel graph with x nodes and y+y' arcs (y for the serialparallel structure and y' for the disruption), a nodepotential scale of u, a minimum cardinality of v for the feasible tension sets. The cost functions of the arcs are defined by two values chosen between 0 and w. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4  #4  ... , #5 ; #6 , #7 ; #8
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is a feasible tension of the arc,
 #5 is the optimum tension of the arc (i.e. where the cost is zero),
 #6 is the unit cost of the tension of the arc when below the optimum,
 #7 is the unit cost of the tension of the arc when above the optimum,
 #8 is not used here.
Option +mintension2 of the Build Graph program. Generates a minimum cost tension problem as a graph with x nodes and y arcs, a nodepotential scale of u, an arctension flexibility of v %. The cost functions of the arcs are defined by a value chosen between 0 and w. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4 , #5 , #6 ; #7 ; #8
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is the minimum tension of the arc,
 #5 is the maximum tension of the arc,
 #6 is the optimum tension of the arc (i.e. where the cost is zero),
 #7 is the unit cost of the tension of the arc,
 #8 is not used here.
Option +mintension2s of the Build Graph program. Generates a minimum cost tension problem as a serialparallel graph with x nodes and y+y' arcs (y for the serialparallel structure and y' for the disruption), a nodepotential scale of u, an arctension flexibility of v %. The cost functions of the arcs are defined by a value chosen between 0 and w. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4 , #5 , #6 ; #7 ; #8
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is the minimum tension of the arc,
 #5 is the maximum tension of the arc,
 #6 is the optimum tension of the arc (i.e. where the cost is zero),
 #7 is the unit cost of the tension of the arc,
 #8 is not used here.
Option +mintension3 of the Build Graph program. Generates a minimum cost tension problem as a graph with x nodes and y arcs, a nodepotential scale of u, an arctension flexibility of v %. The cost functions will be supposed convex and defined as:
log(tolerance^{2}/(tension(optimumtolerance))*((optimum+tolerance)tension))
so its definition domain remains in the interval defined by the tolerance around the optimum tension (i.e. where the cost is zero) of the arc. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4 , #5 ; #6
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is the optimum tension of the arc,
 #5 is the tolerance around the optimum tension of the arc,
 #6 is not used here.
Option +mintension4 of the Build Graph program. Generates a minimum cost tension problem as a graph with x nodes and y arcs, a nodepotential scale of u, an arctension flexibility of v %. The cost functions of the arcs are convex piecewise linear (with 2p pieces), the maximum derivative is w. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4 , #5 , #6 ; #7  #8 , #7  #8 , ... ; #9
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is the minimum tension of the arc,
 #5 is the maximum tension of the arc,
 #6 is the optimum tension of the arc (i.e. where the cost is zero),
 #7 is the length of a piece of the cost function of the arc,
 #8 is the slope of a piece of the cost function of the arc,
 #9 is not used here.
Option +mintension4s of the Build Graph program. Generates a minimum cost tension problem as a serialparallel graph with x nodes and y+y' arcs (y for the serialparallel structure and y' for the disruption), a nodepotential scale of u, an arctension flexibility of v %. The cost functions of the arcs are convex piecewise linear (with 2p pieces), the maximum derivative is w. The output format is defined as follows:
node #1 = #2
 #1 is the number of the node,
 #2 is not used here.
arc #1 = #2 , #3 ; #4 , #5 , #6 ; #7  #8 , #7  #8 , ... ; #9
 #1 is the number of the arc,
 #2 is the source node number of the arc,
 #3 is the target node number of the arc,
 #4 is the minimum tension of the arc,
 #5 is the maximum tension of the arc,
 #6 is the optimum tension of the arc (i.e. where the cost is zero),
 #7 is the length of a piece of the cost function of the arc,
 #8 is the slope of a piece of the cost function of the arc,
 #9 is not used here.
